cyrus-smtptest(1) on Linux
The text 555ecfde0f39, as Debian 10 (Buster) shipped it.
Cyrus IMAP documentation Interactive SMTP test program
Flags it lists
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-a -
-c -
-f -
-i -
-k -
-l -
-m -
-n -
-o -
-p -
-r -
-s -
-t -
-u -
-v -
-w