[Mail] Lots of system email log error messages

[ArchPrime]

Hi, my system email log is showing a lot of error messages from some recipients of mass emails each time.

Most of the errors follow one of the three patterns below :


The mail server did not understand the DATA command


The mail server does not understand the RCPT TO command. Reason: 354 Enter message, ending with "." on a line by itself


The mail server does not understand the MAIL FROM command. Reason: N/A


How do I identify and resolve the source of these errors?  

MyBB mail is set to use SMTP, and the smtp settings are as provided by my web host for the free email account associated with my hosted domain.
Some recipients receive messages no problem with current settings, but many do not.


Further to this, when I send a test message to https://www.mail-tester.com using the 'mail thread to a friend' function within MyBB, the message is reported as looking quite spammy to mail-tester.com (score 4.9/10)

Could this be connected in any way with the errors above?

Main reasons for bad spamminess score seem to be: 

Your message is not signed with DKIM - even though my mail host DNS settings includes a DKIM setting for this domain

Your message does not contain a List-Unsubscribe header - how do I get MYBB to include one?

You are not allowed to use one of your sender email addresses - possibly because I set my nominated myBB forum administrator email address to be my personal address, which is a hosted email account on another domain from the one sending the forum system generated mails.  How do I successfully implement a 'sender' address in mass mails that is not on the myBB mass mail sending domain without making mass mail messages look spammy?  



Any help would be much appreciated!

[Jex]

Hello dear ArchPrime, 
Please read this subject:  https://community.mybb.com/thread-147566.html

[ArchPrime]

Hello dear ArchPrime, 
Please read this subject:  https://community.mybb.com/thread-147566.html

Hi, thanks for the suggestion, which relates to one of the error messages I listed, but there seems to be no resolution to that error message identified in that thread - 'correct' settings for smtp email are not given.

In my case, I am using the SMTP settings provided by my webhost. 
Some system emails gets through with current settings, some do not.

[KuJoe]

Without knowing the SMTP settings or logs it's a little hard to troubleshoot SMTP issues. Can you post the settings without the real e-mail address/username and password?

Alternatively you can look into a SMTP service like https://sendgrid.com/ which has a free plan that should be fine for most forums, MyBB is pretty picky when it comes to SMTP I've learned recently (I had 2 similarly configured SMTP servers and MyBB would only work with one of them for some reason).

[ArchPrime]

Without knowing the SMTP settings or logs it's a little hard to troubleshoot SMTP issues. Can you post the settings without the real e-mail address/username and password?

Alternatively you can look into a SMTP service like https://sendgrid.com/ which has a free plan that should be fine for most forums, MyBB is pretty picky when it comes to SMTP I've learned recently (I had 2 similarly configured SMTP servers and MyBB would only work with one of them for some reason).

Thanks KuJoe

SMTP settings nominated by my webhost are:


Username:
[email protected]
Password:
xxxxx
Incoming Server:
mail.nzarchitecture.net.nz

• IMAP Port: 993
   
  
  
• POP3 Port: 995
  

Outgoing Server:
mail.nzarchitecture.net.nz

• SMTP Port: 465
  

IMAP, POP3, and SMTP require authentication.

Settings in my forum mail config are:


Mail handler
SMTP mail 
SMTP hostname
mail.nzarchitecture.net.nz
SMTP port
The port number of the SMTP server through which mail should be sent.
465
SMTP username
xxxxx@nzarchitecture.net.nz  (same email address)

SMTP password
xxxx (same password, pasted in)

SMTP Encryption Mode
SSL encryption 

Mail Logging
Log everything

Add message ID in mail headers
No


Does this help?

[KuJoe]

Try using port 587 with TLS and see if that helps.

[ArchPrime]

Thanks KuJoe

Frustratingly, MYBB says I have reached my limit of 10 messages in 24 hours  - so I cannot try for another whole day.

Can't see a setting anywhere to temporarily relax this restriction, or to otherwise discreetly test mailing (to only a nominated recipient) - should there be one?

[KuJoe]

Thanks KuJoe

Frustratingly, MYBB says I have reached my limit of 10 messages in 24 hours  - so I cannot try for another whole day.

Can't see a setting anywhere to temporarily relax this restriction, or to otherwise discreetly test mailing (to only a nominated recipient) - should there be one?

You can edit that number in AdminCP -> Users & Groups -> Groups -> <Usergroup> -> Miscellaneous

[ArchPrime]

Thanks KuJoe

Frustratingly, MYBB says I have reached my limit of 10 messages in 24 hours  - so I cannot try for another whole day.

Can't see a setting anywhere to temporarily relax this restriction, or to otherwise discreetly test mailing (to only a nominated recipient) - should there be one?

You can edit that number in AdminCP -> Users & Groups -> Groups -> <Usergroup> -> Miscellaneous

Thanks KuJoe

I have now switched to TLS and port 587 for SMTP, and emails are now mostly getting through, though I am still getting those three error reports for some recipients:

'The mail server does not understand the MAIL FROM command. Reason: N/A'

'The mail server did not understand the DATA command'

'The mail server does not understand the RCPT TO command. Reason: 354 Enter message, ending with "." on a line by itself'


https://www.mail-tester.com is now giving my forum messages a rating of 9.9/10 after I tweaked my domain DNS records to eliminate reported errors  with SPF &  DKIM records (turns out my host switches sending IP address from time to time to reduce domain reputation loss issues) - and so messages should now be pretty good at not being detected as spam.

That said, when sending a single test message to myself, it always ends up in my spam folder.

Two minor possibly contributing factors reported by mail-tester.com are 

'Missing Message-Id: header'

and 

'Your message does not contain a List-Unsubscribe header'

How can system  messages be made to include these headers?

[Lange20]

Yes using port 587 would help...Just try that once and it should give u a sigh of relief