Editing Email (section)

==Issues==
{{More citations needed section|date=October 2016}}

===Attachment size limitation===
{{Main|Email attachment}}
Email messages may have one or more attachments, which are additional files that are appended to the email. Typical attachments include [[Microsoft Word]] documents, [[PDF]] documents, and scanned images of paper documents. In principle, there is no technical restriction on the size or number of attachments. However, in practice, email clients, [[server (computing)|server]]s, and Internet service providers implement various limitations on the size of files, or complete email – typically to 25MB or less.<ref>{{cite web |url-status=live |url=https://exchangepedia.com/2007/09/exchange-server-2007-setting-message-size-limits.html |title=Set Message Size Limits in Exchange 2010 and Exchange 2007 |archive-url=https://web.archive.org/web/20130212114611/https://exchangepedia.com/2007/09/exchange-server-2007-setting-message-size-limits.html |archive-date=2013-02-12 |first1=Bharat |last1=Suneja |website=Exchangepedia |date=September 10, 2007 }}</ref><ref>{{Cite web |last=Humphries |first=Matthew |date=Jun 29, 2009 |title=Google updates file size limits for Gmail and YouTube |url=https://www.geek.com/articles/news/google-updates-file-size-limits-for-gmail-and-youtube-20090629 |url-status=dead |archive-url=https://web.archive.org/web/20111219141547/https://www.geek.com/articles/news/google-updates-file-size-limits-for-gmail-and-youtube-20090629 |archive-date=Dec 19, 2011 |website=Geek.com}}</ref><ref>[https://mail.google.com/support/bin/answer.py?answer=8770&topic=1517 "Maximum attachment size", Gmail Help.] {{Webarchive|url=https://web.archive.org/web/20111015232245/http://mail.google.com/support/bin/answer.py?answer=8770&topic=1517 |date=October 15, 2011 }}.</ref> Furthermore, due to technical reasons, attachment sizes as seen by these transport systems can differ from what the user sees,<ref>{{cite magazine |last=Walther |first=Henrik |date=January 2009 |url=https://docs.microsoft.com/en-us/previous-versions/technet-magazine/dd314394(v=msdn.10) |title=Mysterious Attachment Size Increases, Replicating Public Folders, and More |magazine=[[TechNet Magazine]] |via=[[Microsoft Docs]] |access-date=2021-11-07}} [https://docs.microsoft.com/en-us/previous-versions/technet-magazine/cc135877(v=msdn.10) Exchange Queue & A].</ref> which can be confusing to senders when trying to assess whether they can safely send a file by email. Where larger files need to be shared, various [[file hosting service]]s are available and commonly used.<ref>[https://support.office.com/en-us/article/Send-large-files-to-other-people-7005da19-607a-47d5-b2c5-8f3982c6cc83 "Send large files to other people"] {{webarchive|url=https://web.archive.org/web/20160807110751/https://support.office.com/en-us/article/Send-large-files-to-other-people-7005da19-607a-47d5-b2c5-8f3982c6cc83 |date=2016-08-07 }}, Microsoft.com</ref><ref>[https://www.makeuseof.com/tag/8-ways-to-email-large-attachments/ "8 ways to email large attachments"] {{webarchive|url=https://web.archive.org/web/20160702171053/https://www.makeuseof.com/tag/8-ways-to-email-large-attachments/ |date=2016-07-02 }}, Chris Hoffman, December 21, 2012, makeuseof.com</ref>

===Information overload===
The ubiquity of email for knowledge workers and "white collar" employees has led to concerns that recipients face an "[[information overload]]" in dealing with increasing volumes of email.<ref>{{cite web|last=Radicati|first=Sara|title=Email Statistics Report, 2010|url=https://www.radicati.com/wp/wp-content/uploads/2010/04/Email-Statistics-Report-2010-2014-Executive-Summary2.pdf|url-status=live|archive-url=https://web.archive.org/web/20110901222039/https://www.radicati.com/wp/wp-content/uploads/2010/04/Email-Statistics-Report-2010-2014-Executive-Summary2.pdf|archive-date=2011-09-01}}</ref><ref>{{cite news|last=Gross|first=Doug|title=Happy Information Overload Day!|url=https://edition.cnn.com/2010/TECH/web/10/20/information.overload.day/index.html|work=CNN|date=October 20, 2010|url-status=live|archive-url=https://web.archive.org/web/20151023041454/https://edition.cnn.com/2010/TECH/web/10/20/information.overload.day/index.html|archive-date=October 23, 2015|access-date=March 24, 2019}}</ref> With the growth in mobile devices, by default employees may also receive work-related emails outside of their working day. This can lead to increased stress and decreased satisfaction with work. Some observers even argue it could have a significant negative economic effect,<ref>{{cite news|url=https://www.nytimes.com/2008/04/20/technology/20digi.html|title=Struggling to Evade the E-Mail Tsunami|date=2008-04-20|newspaper=The New York Times|first=Randall|last=Stross|access-date=May 1, 2010|url-status=live|archive-url=https://web.archive.org/web/20090417094850/https://www.nytimes.com/2008/04/20/technology/20digi.html|archive-date=April 17, 2009}}</ref> as efforts to read the many emails could reduce [[productivity]].

===Spam===
{{Main|Email spam}}
Email "spam" is unsolicited bulk email. The low cost of sending such email meant that, by 2003, up to 30% of total email traffic was spam,<ref>{{cite web|url=https://www.sitepronews.com/2015/05/04/seeing-spam-how-to-take-care-of-your-google-analytics-data/|title=Seeing Spam? How To Take Care of Your Google Analytics Data|website=sitepronews.com|access-date=5 September 2017|url-status=live|archive-url=https://web.archive.org/web/20171107005139/https://www.sitepronews.com/2015/05/04/seeing-spam-how-to-take-care-of-your-google-analytics-data/|archive-date=7 November 2017|date=2015-05-04}}</ref><ref>Rich Kawanagh. The top ten email spam list of 2005. ITVibe news, 2006, January 02, [https://itvibe.com/news/3837/ ITvibe.com] {{webarchive|url=https://web.archive.org/web/20080720071624/https://itvibe.com/news/3837/ |date=2008-07-20 }}</ref><ref>How Microsoft is losing the war on spam [https://dir.salon.com/story/tech/feature/2005/01/19/microsoft_spam/index.html Salon.com] {{webarchive|url=https://web.archive.org/web/20080629050141/https://dir.salon.com/story/tech/feature/2005/01/19/microsoft_spam/index.html |date=2008-06-29 }}</ref> and was threatening the usefulness of email as a practical tool. The US [[CAN-SPAM Act of 2003]] and similar laws elsewhere<ref>Spam Bill 2003 ([https://www.aph.gov.au/library/pubs/bd/2003-04/04bd045.pdf PDF] {{webarchive|url=https://web.archive.org/web/20060911062331/https://www.aph.gov.au/library/pubs/bd/2003-04/04bd045.pdf |date=2006-09-11 }})</ref> had some impact, and a number of effective [[anti-spam techniques (email)|anti-spam techniques]] now largely mitigate the impact of spam by filtering or rejecting it for most users,<ref>[https://www.wired.com/2015/07/google-says-ai-catches-99-9-percent-gmail-spam/ "Google Says Its AI Catches 99.9 Percent of Gmail Spam"] {{webarchive|url=https://web.archive.org/web/20160916054313/https://www.wired.com/2015/07/google-says-ai-catches-99-9-percent-gmail-spam/ |date=2016-09-16 }}, Cade Metz, July 09 2015, wired.com</ref> but the volume sent is still very high&mdash;and increasingly consists not of advertisements for products, but malicious content or links.<ref>[https://securelist.com/analysis/quarterly-spam-reports/74682/spam-and-phishing-in-q1-2016/ "Spam and phishing in Q1 2016"] {{webarchive|url=https://web.archive.org/web/20160809154745/https://securelist.com/analysis/quarterly-spam-reports/74682/spam-and-phishing-in-q1-2016/ |date=2016-08-09 }},  May 12, 2016, securelist.com</ref> In September 2017, for example, the proportion of spam to legitimate email rose to 59.56%.<ref>{{Cite web|url=https://usa.kaspersky.com/about/press-releases/2018_fifa-2018-and-bitcoin-among-2017-most-luring-topics|title=Kaspersky Lab Spam and Phishing report|date=May 26, 2021|access-date=July 17, 2018|archive-date=July 17, 2018|archive-url=https://web.archive.org/web/20180717183438/https://usa.kaspersky.com/about/press-releases/2018_fifa-2018-and-bitcoin-among-2017-most-luring-topics|url-status=live}}</ref> The percentage of spam email in 2021 is estimated to be 85%.<ref>{{Cite web|url=https://www.thexyz.com/blog/2021-email-usage-statistics/|title=2021 Email Usage Statistics|date=October 5, 2021|access-date=October 5, 2021|archive-date=October 5, 2021|archive-url=https://web.archive.org/web/20211005234608/https://www.thexyz.com/blog/2021-email-usage-statistics/|url-status=live}}</ref>{{better source needed|date=October 2021}}

===Malware===
Emails are a major vector for the distribution of [[malware]].<ref>{{Cite web |last=Waichulis |first=Arin |date=2024-04-05 |title=Security Bite: iCloud Mail, Gmail, others shockingly bad at detecting malware, study finds |url=https://9to5mac.com/2024/04/05/security-bite-icloud-mail-gmail-others-shockingly-bad-at-detecting-malware-study-finds/ |access-date=2024-05-27 |website=9to5Mac |language=en-US}}</ref> This is often achieved by attaching malicious programs to the message and persuading potential victims to open the file.<ref>{{Cite web |title=When are email attachments safe to open? |url=https://www.cloudflare.com/en-gb/learning/email-security/email-attachments/ |access-date=2024-05-27 |website=[[Cloudflare]]}}</ref> Types of malware distributed via email include [[computer worm]]s<ref>{{Cite web |last=Griffiths |first=James |date=2020-05-02 |title=How a badly-coded computer virus caused billions in damage {{!}} CNN Business |url=https://www.cnn.com/2020/05/01/tech/iloveyou-virus-computer-security-intl-hnk/index.html |access-date=2024-05-27 |website=[[CNN]] |language=en}}</ref> and [[ransomware]].<ref>{{Cite web |last=French |first=Laura |date=2024-05-14 |title=LockBit ransomware spread in millions of emails via Phorpiex botnet |url=https://www.scmagazine.com/news/lockbit-ransomware-spread-in-millions-of-emails-via-phorpiex-botnet |access-date=2024-05-27 |website=SC Media |language=en}}</ref>

===Email spoofing===
{{Main|Email spoofing}}
[[Email spoofing]] occurs when the email message header is designed to make the message appear to come from a known or trusted source. [[Email spam]] and [[phishing]] methods typically use spoofing to mislead the recipient about the true message origin. Email spoofing may be done as a prank, or as part of a criminal effort to defraud an individual or organization. An example of a potentially fraudulent email spoofing is if an individual creates an email that appears to be an invoice from a major company, and then sends it to one or more recipients. In some cases, these fraudulent emails incorporate the logo of the purported organization and even the email address may appear legitimate.

===Email bombing===
{{main|Email bomb}}

[[Email bomb]]ing is the intentional sending of large volumes of messages to a target address. The overloading of the target email address can render it unusable and can even cause the mail server to crash.

===Privacy concerns===
{{Main|Email privacy}}

Today it can be important to distinguish between the Internet and internal email systems. Internet email may travel and be stored on networks and computers without the sender's or the recipient's control. During the transit time it is possible that third parties read or even modify the content. Internal mail systems, in which the information never leaves the organizational network, may be more secure, although [[information technology]] personnel and others whose function may involve monitoring or managing may be accessing the email of other employees.

Email privacy, without some security precautions, can be compromised because:
* email messages are generally not encrypted.
* email messages have to go through intermediate computers before reaching their destination, meaning it is relatively easy for others to intercept and read messages.
* many Internet Service Providers (ISP) store copies of email messages on their mail servers before they are delivered. The backups of these can remain for up to several months on their server, despite deletion from the mailbox.
* the "Received:"-fields and other information in the email can often identify the sender, preventing anonymous communication.
* [[web bug]]s invisibly embedded in HTML content can alert the sender of any email whenever an email is rendered as HTML (some e-mail clients do this when the user reads, or re-reads the e-mail) and from which IP address. It can also reveal whether an email was read on a smartphone or a PC, or Apple Mac device via the [[user agent string]].

There are [[cryptography]] applications that can serve as a remedy to one or more of the above. For example, [[Virtual Private Network]]s or the [[Tor (network)|Tor network]] can be used to encrypt traffic from the user machine to a safer network while [[GNU Privacy Guard|GPG]], [[Pretty Good Privacy|PGP]], SMEmail,<ref>[https://www.arxiv.org/pdf/1002.3176 SMEmail – A New Protocol for the Secure E-mail in Mobile Environments], Proceedings of the Australian Telecommunications Networks and Applications Conference (ATNAC'08), pp. 39–44, Adelaide, Australia, Dec. 2008.</ref> or [[S/MIME]] can be used for [[end-to-end principle|end-to-end]] message encryption, and SMTP STARTTLS or SMTP over [[Transport Layer Security]]/Secure Sockets Layer can be used to encrypt communications for a single mail hop between the SMTP client and the SMTP server.

Additionally, many [[mail user agent]]s do not protect logins and passwords, making them easy to intercept by an attacker. Encrypted authentication schemes such as [[Simple Authentication and Security Layer|SASL]] prevent this. Finally, the attached files share many of the same hazards as those found in [[Peer-to-peer|peer-to-peer filesharing]]. Attached files may contain [[Trojan horse (computing)|trojans]] or [[Computer virus|viruses]].

===Legal contracts===
It is possible for an exchange of emails to form a binding contract, so users must be careful about what they send through email correspondence.<ref>{{Cite web|url=https://www.law.com/newyorklawjournal/almID/1202794877741/When-Email-Exchanges-Become-Binding-Contracts/|title=When Email Exchanges Become Binding Contracts|website=law.com|access-date=December 6, 2019|archive-date=June 19, 2019|archive-url=https://web.archive.org/web/20190619151252/https://www.law.com/newyorklawjournal/almID/1202794877741/When-Email-Exchanges-Become-Binding-Contracts/|url-status=live}}</ref><ref>{{cite journal |last1=Catarina |first1=Jessica |last2=Feitel |first2=Jesse |title=Inadvertent Contract Formation via Email under New York Law: An Update |journal=[[Syracuse Law Review]] |date=2019 |volume=69 |url=https://lawreview.syr.edu/wp-content/uploads/2020/01/K-Contracts-Article.pdf}}</ref> A signature block on an email may be interpreted as satisfying a signature requirement for a contract.<ref>{{cite news|last1=Corfield|first1=Gareth|title=UK court ruling says email signature blocks can sign binding contracts|url=https://www.theregister.co.uk/2019/09/30/email_signature_legally_binding_contract/|access-date=6 December 2019|work=[[The Register]]|archive-date=October 17, 2019|archive-url=https://web.archive.org/web/20191017063749/https://www.theregister.co.uk/2019/09/30/email_signature_legally_binding_contract/|url-status=live|date=30 September 2019}}</ref>

===Flaming===
[[Flaming (Internet)|Flaming]] occurs when a person sends a message (or many messages) with angry or antagonistic content. The term is derived from the use of the word ''incendiary'' to describe particularly heated email discussions. The ease and impersonality of email communications mean that the [[social norms]] that encourage civility in person or via telephone do not exist and civility may be forgotten.<ref>{{cite journal|author1=S. Kiesler |author2=D. Zubrow |author3=A.M. Moses |author4=V. Geller |title=Affect in computer-mediated communication: an experiment in synchronous terminal-to-terminal discussion|journal=Human-Computer Interaction|volume=1|pages=77–104|year=1985|doi=10.1207/s15327051hci0101_3}}</ref>

===Email bankruptcy===
{{main|Email bankruptcy}}
Also known as "email fatigue", email bankruptcy is when a user ignores a large number of email messages after falling behind in reading and answering them. The reason for falling behind is often due to information overload and a general sense there is so much information that it is not possible to read it all. As a solution, people occasionally send a "boilerplate" message explaining that their email inbox is full, and that they are in the process of clearing out all the messages. [[Harvard University]] law professor [[Lawrence Lessig]] is credited with coining this term, but he may only have popularized it.<ref>{{cite news|title=All We Are Saying.|url=https://www.nytimes.com/2007/12/23/weekinreview/23buzzwords.html|newspaper=The New York Times|date=December 23, 2007|access-date=2007-12-24|first=Grant|last=Barrett|url-status=live|archive-url=https://web.archive.org/web/20090417094849/https://www.nytimes.com/2007/12/23/weekinreview/23buzzwords.html|archive-date=April 17, 2009}}</ref>

===Internationalization===
Originally Internet email was completely ASCII text-based. MIME now allows body content text and some header content text in international character sets, but other headers and email addresses using UTF-8, while standardized<ref>{{Cite web|url=https://registry.in/Internationalized_Domain_Names_IDNs|title=Internationalized Domain Names (IDNs) {{!}} Registry.In|website=registry.in|access-date=2016-10-17|url-status=live|archive-url=https://web.archive.org/web/20160513012539/https://registry.in/Internationalized_Domain_Names_IDNs|archive-date=2016-05-13}}</ref> have yet to be widely adopted.<ref name=first>{{cite web|url=https://economictimes.indiatimes.com/tech/internet/datamail-worlds-first-free-linguistic-email-service-supports-eight-india-languages/articleshow/54923001.cms|title=DataMail: World's first free linguistic email service supports eight India languages|url-status=live|archive-url=https://web.archive.org/web/20161022080739/https://economictimes.indiatimes.com/tech/internet/datamail-worlds-first-free-linguistic-email-service-supports-eight-india-languages/articleshow/54923001.cms|archive-date=2016-10-22}}</ref><ref>{{cite web|url=https://digitalconqurer.com/gadgets/made-india-datamail-empowers-russia-email-address-russian-language/|title=Made In India 'Datamail' Empowers Russia With Email Address In Russian Language - Digital Conqueror|date=7 December 2016|url-status=live|archive-url=https://web.archive.org/web/20170305005327/https://digitalconqurer.com/gadgets/made-india-datamail-empowers-russia-email-address-russian-language/|archive-date=5 March 2017}}</ref>
{{further|International email|Email address#Internationalization}}

===Tracking of sent mail===
The original SMTP mail service provides limited mechanisms for tracking a transmitted message, and none for verifying that it has been delivered or read. It requires that each mail server must either deliver it onward or return a failure notice (bounce message), but both software bugs and system failures can cause messages to be lost. To remedy this, the [[Internet Engineering Task Force|IETF]] introduced [[Delivery Status Notification]]s (delivery receipts) and [[Return receipt#Email|Message Disposition Notifications]] (return receipts); however, these are not universally deployed in production.{{Refn|group=nb|A complete Message Tracking mechanism was also defined, but it never gained traction; see RFCs 3885<ref>RFC 3885, ''SMTP Service Extension for Message Tracking''</ref> through 3888.<ref>RFC 3888, ''Message Tracking Model and Requirements''</ref>}}

Many ISPs now deliberately disable non-delivery reports (NDRs) and delivery receipts due to the activities of spammers:
* Delivery Reports can be used to verify whether an address exists and if so, this indicates to a spammer that it is available to be spammed.
* If the spammer uses a forged sender email address ([[email spoofing]]), then the innocent email address that was used can be flooded with NDRs from the many invalid email addresses the spammer may have attempted to mail. These NDRs then constitute spam ([[backscatter (email)|backscatter]]) from the ISP to the innocent user.

In the absence of standard methods, a range of system based around the use of [[web bug]]s have been developed. However, these are often seen as underhand or raising privacy concerns,<ref>{{cite news|url=https://query.nytimes.com/gst/fullpage.html?res=940CE0D9143AF931A15752C1A9669C8B63|title=Software That Tracks E-Mail Is Raising Privacy Concerns|author=Amy Harmon|newspaper=The New York Times|date=2000-11-22|access-date=2012-01-13}}</ref><ref>{{cite web |url=https://email.about.com/od/emailbehindthescenes/a/html_return_rcp.htm |title=About.com |publisher=Email.about.com |date=2013-12-19 |access-date=2014-01-09 |url-status=live |archive-url=https://web.archive.org/web/20160827203219/https://email.about.com/od/emailbehindthescenes/a/html_return_rcp.htm |archive-date=2016-08-27 }}</ref> and only work with email clients that support rendering of HTML. Many mail clients now default to not showing "web content".<ref>[https://www.slipstick.com/outlook/email/microsoft-outlook-web-bugs-blocked-html-images "Outlook: Web Bugs & Blocked HTML Images"] {{webarchive|url=https://web.archive.org/web/20150218074718/https://www.slipstick.com/outlook/email/microsoft-outlook-web-bugs-blocked-html-images/ |date=2015-02-18 }}, slipstick.com</ref> [[Webmail]] providers can also disrupt web bugs by pre-caching images.<ref>[https://arstechnica.com/information-technology/2013/12/gmail-blows-up-e-mail-marketing-by-caching-all-images-on-google-servers/ "Gmail blows up e-mail marketing..."] {{webarchive|url=https://web.archive.org/web/20170607090403/https://arstechnica.com/information-technology/2013/12/gmail-blows-up-e-mail-marketing-by-caching-all-images-on-google-servers/ |date=2017-06-07 }}, Ron Amadeo, Dec 13 2013, Ars Technica</ref>