Werk #20010: Certificate check: STARTTLS is now possible for IMAP

Component

Checks & agents

Title

Certificate check: STARTTLS is now possible for IMAP

Date

Jun 2, 2026

Level

Trivial Change

Class

New Feature

Compatibility

Compatible - no manual interaction needed

Checkmk versions & editions

2.6.0b1 Not yet released	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT
2.5.0p6 Not yet released	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT

When using "Check certificates", you can now select "IMAP STARTTLS" as connection type.

This allows checking the certificate of IMAP servers that require a STARTTLS procedure to use TLS (SSL), for example on port 143.

This change has already been released with Checkmk 2.5.0b1.