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

[larsen]

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"?
https://tldp.org/HOWTO/Spam-Filtering-for-MX/smtpchecks.html

And I found this for Postfix. Same as "SMTP HELO checks"?
http://www.postfix.org/SMTPD_ACCESS_README.html

• 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)?

 

[steven99]

No disadvantage. HELO is part of the SMTP RFC I am sure and any MTA not following RFCs are likely spammers anyhow.