What is the meaning of "SMTP HELO checks" (mail proxy options)?


Feb 28, 2020
The admin guide could be a little bit more verbose than just "Use SMTP HELO tests." (for all the options) ;-)

The general information here applies to "SMTP HELO checks"?

And I found this for Postfix. Same as "SMTP HELO checks"?
  • Requiring that the client sends the HELO or EHLO command before sending the MAIL FROM or ETRN command. This may cause problems with home-grown applications that send mail. For this reason, the requirement is disabled by default ("smtpd_helo_required = no").
This is not the default value so is there a disadvantage when activated (besides the one mentioned before)?


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