MailKit 2.5.1
MailKit is an Open Source cross-platform .NET mail-client library that is based on MimeKit and optimized for mobile devices.
Features include:
* HTTP, Socks4, Socks4a and Socks5 proxy support.
* SASL Authentication via SCRAM-SHA-256, SCRAM-SHA-1, NTLM, DIGEST-MD5, CRAM-MD5, LOGIN, PLAIN, and XOAUTH2.
* A fully-cancellable SmtpClient with support for STARTTLS, 8BITMIME, BINARYMIME, ENHANCEDSTATUSCODES, SIZE, DSN, PIPELINING and SMTPUTF8.
* A fully-cancellable Pop3Client with support for STLS, UIDL, APOP, PIPELINING, UTF8, and LANG.
* A fully-cancellable ImapClient with support for ACL, QUOTA, LITERAL+, IDLE, NAMESPACE, ID, CHILDREN, LOGINDISABLED, STARTTLS, MULTIAPPEND, UNSELECT, UIDPLUS, CONDSTORE, ESEARCH, SASL-IR, COMPRESS, WITHIN, ENABLE, QRESYNC, SORT, THREAD, ANNOTATE, LIST-EXTENDED, ESORT, METADATA / METADATA-SERVER, NOTIFY, FILTERS, LIST-STATUS, SORT=DISPLAY, SPECIAL-USE / CREATE-SPECIAL-USE, SEARCH=FUZZY, MOVE, UTF8=ACCEPT / UTF8=ONLY, LITERAL-, APPENDLIMIT, STATUS=SIZE, OBJECTID, XLIST, and X-GM-EXT1.
* Client-side sorting and threading of messages (the Ordinal Subject and the Jamie Zawinski threading algorithms are supported).
* Asynchronous versions of all methods that hit the network.
* S/MIME, OpenPGP, DKIM and ARC support via MimeKit.
* Microsoft TNEF support via MimeKit.
No packages depend on MailKit.
* Fixed the IMAP ENVELOPE parser to have a more lenient fallback if it fails to be able to parse the Message-Id token value. (issue #976)
* Fixed MailService.DefaultServerCertificateValidationCallback() to compare certificates by their hashes rather than via Object.Equals(). (issue #977)
* Added work-around for IMAP servers that send `-1` as a line count or octet count in the BODYSTRUCTURE response.
API Changes Since 2.0.x:
* Obsoleted SearchQuery.HasCustomFlags() and SearchQuery.DoesNotHaveCustomFlags(). These are now SearchQuery.HasKeywords() and SearchQuery.NotKeywords(), respectively.
* Obsoleted SearchQuery.DoesNotHaveFlags() in favor of SearchQuery.NotFlags().
* Obsoleted the IMessageSummary.UserFlags property in favor of IMessageSummary.Keywords.
* Obsoleted the MessageFlagsChangedEventArgs.UserFlags property in favor of MessageFlagsChangedEventArgs.Keywords.
* All IMailFolder.Fetch and IMailFolder.FetchAsync methods that took a HashSet<string> userFlags argument now take an IEnumerable<string> keywords argument. Note: this only affects you if your code used named method parameters (e.g. userFlags: myUserFlags).
Note to users upgrading from MailKit 1.x:
In order to authenticate using the XOAUTH2 SASL mechanism, you must now use the following approach:
client.Authenticate (new SaslMechanismOAuth2 (username, auth_token));
.NET Framework 4.5
- MimeKit (>= 2.5.1)
.NET Standard 2.0
- MimeKit (>= 2.5.1)
- System.Net.Security (>= 4.3.2)
- System.Net.NameResolution (>= 4.3.0)
- System.Runtime.Serialization.Primitives (>= 4.3.0)
.NET Standard 1.6
- System.Net.Security (>= 4.3.2)
- System.Net.NameResolution (>= 4.3.0)
- System.Runtime.Serialization.Primitives (>= 4.3.0)
- MimeKit (>= 2.5.1)
.NET Standard 1.3
- MimeKit (>= 2.5.1)
- System.Net.NameResolution (>= 4.3.0)
- System.Runtime.Serialization.Primitives (>= 4.3.0)
- System.Net.Security (>= 4.3.2)
Xamarin.iOS 0.0
- MimeKit (>= 2.5.1)
MonoAndroid 0.0
- MimeKit (>= 2.5.1)
.NET Framework 4.8
- MimeKit (>= 2.5.1)
.NET Framework 4.7
- MimeKit (>= 2.5.1)
.NET Framework 4.6
- MimeKit (>= 2.5.1)
| Version | Downloads | Last updated |
|---|---|---|
| 4.15.1 | 2 | 2026/4/11 |
| 4.15.0 | 0 | 2026/2/15 |
| 4.14.1 | 0 | 2025/10/13 |
| 4.14.0 | 1 | 2026/4/11 |
| 4.13.0 | 0 | 2025/6/25 |
| 4.12.1 | 1 | 2026/4/11 |
| 4.12.0 | 0 | 2025/4/29 |
| 4.11.0 | 1 | 2026/4/11 |
| 4.10.0 | 1 | 2026/4/11 |
| 4.9.0 | 1 | 2026/4/10 |
| 4.8.0 | 0 | 2024/9/29 |
| 4.7.1.1 | 0 | 2024/7/15 |
| 4.7.1 | 1 | 2026/4/10 |
| 4.7.0 | 1 | 2026/4/10 |
| 4.6.0 | 1 | 2026/4/10 |
| 4.5.0 | 1 | 2026/4/10 |
| 4.4.0 | 1 | 2026/4/10 |
| 4.3.0 | 3 | 2025/8/15 |
| 4.2.0 | 1 | 2026/4/10 |
| 4.1.0 | 2 | 2026/4/9 |
| 4.0.0 | 1 | 2026/4/10 |
| 3.6.0 | 1 | 2026/4/10 |
| 3.5.0 | 1 | 2026/4/10 |
| 3.4.3 | 1 | 2026/4/10 |
| 3.4.2 | 1 | 2026/4/10 |
| 3.4.1 | 1 | 2026/4/10 |
| 3.4.0 | 1 | 2026/4/10 |
| 3.3.0 | 1 | 2026/4/10 |
| 3.2.0 | 1 | 2026/4/10 |
| 3.1.1 | 1 | 2026/4/10 |
| 3.1.0 | 1 | 2026/4/10 |
| 3.0.0 | 1 | 2026/4/10 |
| 2.15.0 | 0 | 2021/8/19 |
| 2.14.0 | 0 | 2021/7/28 |
| 2.13.0 | 0 | 2021/6/12 |
| 2.12.0 | 1 | 2026/4/11 |
| 2.11.1 | 1 | 2026/4/9 |
| 2.11.0 | 1 | 2026/4/11 |
| 2.10.1 | 1 | 2026/4/11 |
| 2.10.0 | 1 | 2026/4/11 |
| 2.9.0 | 1 | 2026/4/10 |
| 2.8.0 | 1 | 2026/4/10 |
| 2.7.0 | 1 | 2026/4/10 |
| 2.6.0 | 1 | 2026/4/10 |
| 2.5.2 | 1 | 2026/4/10 |
| 2.5.1 | 1 | 2026/4/10 |
| 2.5.0 | 1 | 2026/4/10 |
| 2.4.1 | 1 | 2026/4/10 |
| 2.4.0.1 | 0 | 2019/11/5 |
| 2.4.0 | 1 | 2026/4/10 |
| 2.3.2 | 1 | 2026/4/10 |
| 2.3.1.6 | 0 | 2019/9/9 |
| 2.3.1 | 1 | 2026/4/10 |
| 2.3.0 | 1 | 2026/4/10 |
| 2.2.0 | 1 | 2026/4/10 |
| 2.1.5.1 | 0 | 2019/5/13 |
| 2.1.4 | 1 | 2026/4/10 |
| 2.1.3 | 1 | 2026/4/10 |
| 2.1.2 | 1 | 2026/4/10 |
| 2.1.1 | 1 | 2026/4/10 |
| 2.1.0.3 | 0 | 2018/12/7 |
| 2.0.7 | 1 | 2026/4/10 |
| 2.0.6 | 1 | 2026/4/10 |
| 2.0.5 | 1 | 2026/4/10 |
| 2.0.4 | 1 | 2026/4/10 |
| 2.0.3 | 1 | 2026/4/10 |
| 2.0.2 | 1 | 2026/4/10 |
| 2.0.1 | 1 | 2026/4/10 |
| 2.0.0 | 2 | 2025/8/14 |
| 1.22.0 | 2 | 2025/8/14 |
| 1.20.0 | 1 | 2026/4/11 |
| 1.18.1.1 | 0 | 2017/9/4 |
| 1.18.1 | 0 | 2017/9/3 |
| 1.18.0 | 1 | 2026/4/11 |
| 1.16.2 | 1 | 2026/4/11 |
| 1.16.1 | 0 | 2017/5/5 |
| 1.16.0 | 1 | 2026/4/11 |
| 1.14.2 | 1 | 2026/4/10 |
| 1.12.0 | 1 | 2026/4/11 |
| 1.10.2 | 1 | 2026/4/11 |
| 1.10.1 | 0 | 2016/12/4 |
| 1.10.0 | 0 | 2016/10/31 |