openssl s_client -starttls imap -connect imap.example.com:143

Category: Mail Servers & Postfix

openssl s_client -starttls imap -connect imap.example.com:143

Inspect TLS on IMAP with STARTTLS

Tests the IMAP port's STARTTLS upgrade and shows the certificate the server offers, confirming IMAPS readiness. Type `a1 LOGIN user pass` to test credentials manually, or `a1 LOGOUT` to end the session cleanly.
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