IMAP check capability
By nmap
Output example:
PORT STATE SERVICE
143/tcp open imap
|_imap-capabilities: IDLE IMAP4 UNSELECT completed SASL-IR UIDPLUS LOGINDISABLED NAMESPACE OK LITERAL+A0001 CAPABILITY CHILDREN ID MOVE STARTTLS IMAP4rev1
993/tcp open imaps
|_imap-capabilities: UNSELECT SASL-IR LITERAL+A0001 AUTH=NTLM IMAP4rev1 AUTH=GSSAPI IMAP4 OK UIDPLUS completed AUTH=PLAIN CAPABILITY ID NAMESPACE MOVE CHILDREN IDLE