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node.jsimap

is it possible to detect IMAP protocol version?

I am using Nodejs to establish IMAP IDLE connection for email client. Is there any possibility to detect IMAP protocol version when it establish connection.

Solution

  • All IMAP servers today run the same version, 4rev1. Versions 1, 2, 3 and 4 are long gone.

    Further, all servers today support one or more extensions. The CAPABILITY command returns the list of extensions. For gmail:

    openssl s_client -connect imap.gmail.com:993 -crlf

a capability
* CAPABILITY IMAP4rev1 UNSELECT IDLE NAMESPACE QUOTA ID XLIST CHILDREN X-GM-EXT-1 XYZZY SASL-IR AUTH=XOAUTH AUTH=XOAUTH2 AUTH=PLAIN AUTH=PLAIN-CLIENTTOKEN
a OK Thats all she wrote! j14mb28178795bkd

    So gmail supports IDLE and about a dozen more extensions.