SMTP 5xx errors

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Simple User
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SMTP 5xx errors

Post by Simple User » 2022-07-05 11:03

Hi,

I've noticed that if a remote SMTP servers answers with a 5xx error message, hmailserver still tries to resend that email.
5xx errors are permanent failures, therefor shouldn't be retried but immediately failed.

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johang
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Re: SMTP 5xx errors

Post by johang » 2022-07-05 11:57

Simple User wrote:
2022-07-05 11:03
Hi,

I've noticed that if a remote SMTP servers answers with a 5xx error message, hmailserver still tries to resend that email.
5xx errors are permanent failures, therefor shouldn't be retried but immediately failed.
could you provide an example ?
for example: if i send an email to a non existing emailaddress, i get an 550 back without my hmailserver doing any retries..
( however if i try to send same email ( bad emailadress) to a server that greylists or use GlobalView from Cyren, i get error 421, and my hmailserver will retry... until it gets a 550 and gives me an "Message undeliverable" in my mailbox .... )

is it an particular error code that you have problem with ?
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Re: SMTP 5xx errors

Post by Simple User » 2022-07-05 12:45

unfortunately i was cleaning out all our queues but this one had several retries:

"RECEIVED: 550-5.1.1 The email account that you tried to reach does not exist. Please try[nl]550-5.1.1 double-checking the recipient's email address for typos or[nl]550-5.1.1 unnecessary spaces. Learn more at[nl]550 5.1.1 https://support.google.com/mail/?p=NoSuchUser t4-20020a17090605c400b007262d20d6cesi36530114ejt.200 - gsmtp"

Also if a domain doesn't exist it is also retrying, shouldn't this be considered a permanent fault?

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jimimaseye
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Re: SMTP 5xx errors

Post by jimimaseye » 2022-07-05 14:43

Simple User wrote:
2022-07-05 12:45
unfortunately i was cleaning out all our queues but this one had several retries:

"RECEIVED: 550-5.1.1 The email account that you tried to reach does not exist. Please try[nl]550-5.1.1 double-checking the recipient's email address for typos or[nl]550-5.1.1 unnecessary spaces. Learn more at[nl]550 5.1.1 https://support.google.com/mail/?p=NoSuchUser t4-20020a17090605c400b007262d20d6cesi36530114ejt.200 - gsmtp"

Also if a domain doesn't exist it is also retrying, shouldn't this be considered a permanent fault?
This doesn't tell us anything - the log sown doesn't tell us enough. Provide all relevant SMTPD, SMTPC and application entries from the log file.

[Entered by mobile. Excuse my spelling.]
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johang
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Re: SMTP 5xx errors

Post by johang » 2022-07-05 15:04

Simple User wrote:
2022-07-05 12:45
unfortunately i was cleaning out all our queues but this one had several retries:

"RECEIVED: 550-5.1.1 The email account that you tried to reach does not exist. Please try[nl]550-5.1.1 double-checking the recipient's email address for typos or[nl]550-5.1.1 unnecessary spaces. Learn more at[nl]550 5.1.1 https://support.google.com/mail/?p=NoSuchUser t4-20020a17090605c400b007262d20d6cesi36530114ejt.200 - gsmtp"

Also if a domain doesn't exist it is also retrying, shouldn't this be considered a permanent fault?
regarding non existing email account at google:
i see only statusmessage from 1 logline provided by you, which does not bring any clarity what so ever ..

i get this answer within seconds from my mailserver when google responds 550 when sending to non existing user ( NO retries ):

Code: Select all

our message did not reach some or all of the intended recipients.

   Sent: Tue, 5 Jul 2022 14:59:04 +0200
   Subject: test

The following recipient(s) could not be reached:

wohfowiubiubqweviubqieubvuiqbuivbqipeuvbiuv@gmail.com
   Error Type: SMTP
   Remote server (74.125.131.26) issued an error.
   hMailServer sent: RCPT TO:<wohfowiubiubqweviubqieubvuiqbuivbqipeuvbiuv@gmail.com>
   Remote server replied: 550-5.1.1 The email account that you tried to reach does
not exist. Please try
550-5.1.1 double-checking the recipient's email address for typos or
550-5.1.1 unnecessary spaces. Learn more at
550 5.1.1  https://support.google.com/mail/?p=NoSuchUser
bp19-20020a056512159300b0047f8ac733c8si13426844lfb.336 - gsmtp



Regarding non existant domain:
I can understand you want a direct Delivery Status Notification on an email with a non existant recieving domain in an email address
that gets stuck in queue as well for me when i do a test..
( its not a 5.x.x. error though )
nor me or my users are prone to writing the wrong domain though so i havent even noticed it to be a problem.
lets cheat darwin out of his legacy, find a cure for cancer...

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