Re: [Emailcore] Ticket #5: G.5. Remove or deprecate the work-around from code 552 to 452?

[Alexey Melnikov <[e-mail]>]

Hi,

On Tue, Jan 19, 2021, at 4:24 PM, Alexey Melnikov wrote:
> Hi all,
> 
> The first pagaraph of Section 4.5.3.1.10 (Too Many Recipients Code) 
> currently says:
> 
>     RFC 821 [3] incorrectly listed the error where an SMTP server
>     exhausts its implementation limit on the number of RCPT commands
>     ("too many recipients") as having reply code 552.  The correct reply
>     code for this condition is 452.  Clients SHOULD treat a 552 code in
>     this case as a temporary, rather than permanent, failure so the logic
>     below works.
> 
> John noted that this suggestion may have outlived its usefulness
> and/or be inconsistent with current practice. Should it be removed
> and/or explicitly deprecated?

I did a bit of digging and it doesn't look like Sendmail emits 552 or treats it as 442 if received from other MTA.
Postfix code has this commented out with a note that this workaround creates more problems than it solves, due to other meaning of 552.

Do people have information about other MTAs (not necessarily open source) on this topic?

Best Regards,
Alexey