MailBee.NET IMAP Component

MailBee.NET IMAP Component

Manage, download, search and process mails and folders on IMAP4 servers
MailBee.NET Objects bundle includes SMTP, POP3, IMAP, EWS, Security, Antispam, Outlook Converter, Address Validator, PDF components and also BounceMail, HTML, MIME, ICalVCard components which are a free functionality.

MailBee.NET IMAP is a high-performance memory-conservative .NET component for processing e-mails and folders on IMAP4 servers. Can do everything the POP3 component does, and much more: download and manage folders, search, flag, upload, move, copy messages, download message envelopes or any specific parts or attributes of messages, etc. Backed with commercial-grade support.

MailBee.NET IMAP downloads messages in a batch, drastically improving performance.

MailBee.NET IMAP bundle includes a set of MIME objects such as MailMessage and Attachment which are used for e-mail parsing.

Visual Studio


Written in 100% managed code, MailBee.NET IMAP only requires the .NET framework be installed on the computer.

MailBee.NET IMAP can be used in any .NET language including C# and VB.NET. Supported .NET frameworks include .NET 2.0/3.0/3.5/4.0/4.5/4.6/4.7/4.8, both 32-bit and 64-bit.

MailBee.NET also supports .NET Core 1.0/2.0/3.0/3.1, .NET 5.0/.NET 8.0 and newer including ASP.NET Core and Xamarin, UWP (Universal Windows), Azure.

With MailBee.NET Objects license, you also get these MailBee.NET components for free: BounceMail, HTML, MIME, ICalVCard.

Top 100 publisher by ComponentSource

Over the years, MailBee.NET Objects has been among bestsellers on ComponentSource, the world's leading online shop of developer tools.

MailBee.NET IMAP Component fully supports:


  • HTTP
  • SSL/TLS (incl. TLS 1.3)
  • SASL
  • NTLM
  • Kerberos
  • SOCKS4/5
  • HTTP Proxy



Servers & Services

  • MS Exchange
  • Lotus Notes
  • GroupWise
  • IMail
  • MailEnable
  • AxiGen
  • SmarterMail
  • SurgeMail
  • MDaemon
  • Kerio
  • CommuniGate
  • hMailServer
  • Qmail
  • Courier
  • Dovecot
  • Cyrus
  • Zimbra

...and any POP3/SMTP/IMAP compliant servers

IMAP Object

  • Download entire messages, headers only, envelopes, or anything else which can be returned by IMAP's FETCH command
  • Download and manage folders (international folder names fully supported)
  • Get special folder flags like Sent, Drafts, Trash (if server supports XLIST)
  • Download messages through a proxy server
  • Get already downloaded messages/envelopes if the entire operation failed in the middle
  • Supports secure TLS/SSL connections out-of-box (supports Gmail, etc)
  • Async/await methods
  • Upload a message in a folder
  • Copy messages between folders
  • UNIQUE Move messages between folders
  • UNIQUE Obtain UID of uploaded/copied/moved messages if the server supports UIDPLUS
  • Delete messages
  • Examine and set message flags
  • Expunge (i.e. purge) deleted messages
  • UNIQUE Expunge specific deleted messages
  • Search messages
  • Search and sort messages if IMAP SORT is supported by the server
  • IDLE mode to get notifications from the server on mailbox status change
  • Secure authentication (CRAM-MD5, DIGEST-MD5, NTLM, Kerberos)
  • UNIQUE Windows Integrated Authentication (authenticate using the current Windows user credentials)
  • User-defined authentication methods
  • UNIQUE Get account quota and used space size if the server supports QUOTA
  • Automatic detection and use of IMAP capabilities
  • UNIQUE Faster upload if the server supports LITERAL+
  • UNIQUE Can tolerate incorrectly formatted responses from the server (keeping the application informed if this happens)
  • Provides methods for converting IMAP strings, dates, international folder names, etc
  • Logging IMAP session into a file or memory
  • Returns e-mails as MailMessage objects which can be interchanged with other objects (Smtp, etc)
  • Can check DomainKeys/DKIM signatures of e-mails (using SMTP component)
  • Parses bounced e-mails and delivery notifications
  • Send user-defined commands to the server
  • Rich set of events and asynchronous processing options
  • Can be placed on the form or created in the code

Imap Object reference...

MailMessage Object

  • Import and export from/into System.Net.Mail.MailMessage
  • Used by Smtp object as outgoing e-mail
  • Returned by Pop3 and Imap objects as incoming e-mail
  • Multiple recipients (To/CC/BCC)
  • Multiple attachments
  • Advanced mail merge
  • Can be encrypted, signed, decrypted, or verified with Smime object
  • Easy access to plain-text and HTML body
  • Full support of international encodings and charsets
  • Can extract attachments from MS-TNEF (winmail.dat) files
  • Access to every MIME part
  • Access to all message headers
  • Access to message timestamps ("Received:" headers)
  • UNIQUEConversion from HTML to plain-text and vice versa including high-lighting of URIs, images, quotations, etc
  • UNIQUEFull support of creating and displaying HTML messages with embedded pictures in desktop and web applications
  • UNIQUEAccess forwarded messages (GetEncapsulatedMessage)
  • Forward message as attachment
  • Import HTML file or web page into e-mail
  • Import & export message data from/into memory, file and stream
  • Serialize into XML and deserialize from XML
  • Base64 and Quoted-Printable
  • Confirm Read & Confirm Receipt
  • Reply-To, Priority, Importance, Sensitivity, etc

MailMessage Object reference...

What's new

Version 12.4

  • .NET 8.0 officially supported

See Version History for details

Version 12.3.1

Version 12.3

  • TLS 1.3 support.

Version 12.2

  • Office 365 OAuth 2.0 support (developer guides and samples available for desktop and ASP.NET Core apps).
  • Documentation improvements.

Version 12.1

  • Separate UWP .NET Standard 2.0 edition for UWP apps targeting Windows 10 Fall Creators Update and newer. Has no Win32 dependencies and can be used in UWP Release builds published in Microsoft Store.
  • Faster and more accurate parser of inline images in e-mails with embedded resources.

Version 12.0

  • .NET Core 2.0 / .NET Standard 2.0 edition revised and improved, including better support of .NET Core 2.1 and 2.2.
  • .NET Standard 2.0 support in UWP. UWP apps targeting Windows 10 Fall Creators Update and newer can use the fully-functional .NET Standard 2.0 edition of MailBee.NET Objects.
  • .NET Core 2.0 sample projects and tutorials added (UWP, console and ASP.NET Core). They feature OAuth 2.0 authentication against Google ( and Microsoft (,, providers along with sending and receiving e-mail using these providers.
  • Improved support of TLS 1.2, now it's selected automatically if supported by the server.
  • Envelope.HasSystemFlag, a helper method to check the envelope for particular IMAP flags.

Clients Say:

"I've been looking at the MailBee.NET application and love it." Matt Yeager
"Thanks again for your help. I like your products..." Ron Hill
"By the way I love your software. Great work thank you." Dennis Drogemuller