P.455, SMTP provides 3 built-in-commands:
VRFY - Validates users
EXPN - Shows the actual delivery addresses of aliases and mailing lists
RCPT TO - Defines the recipients of a message
According to your source Verify (VRFY) and Expand (EXPN) do the same thing. Upon further research it seems that VRFY is used to verify an (email) address and EXPN is used to determine the membership of a mailing list.
Src(s): https://cr.yp.to/smtp/vrfy.html
http://www.smtp-server.com/simple_mail_verifying.htm
Use the VRFY command to verify whether a given mailbox exists on the local host.
https://www.ibm.com/docs/en/zos/2.1.0?topic=sc-vrfy-command-verify-whether-mailbox-exists-local-host
A voting comment increases the vote count for the chosen answer by one.
Upvoting a comment with a selected answer will also increase the vote count towards that answer by one.
So if you see a comment that you already agree with, you can upvote it instead of posting a new comment.
EngnSu
Highly Voted 11 months agoDaniel8660
Most Recent 6 months, 3 weeks agoAverage_Joe
1 year agoAverage_Joe
1 year agoadespino
1 year, 8 months agoANDRESCB1988
1 year, 9 months agoamericaman80
2 years ago