Repeating sending mails

[bkova]

Hi,
we are using Ability mail server almost 10 years and we are now on using ver 3.1.0.
We have organisation in which we monthly automaticaly sending reports (from our SQL server) to many diferent domains and emails of our customers (cca 500 e-mails). Some of clients complaining that they receive more e-mails (till 5 by some clients). We checked source logs and we can proof that SQl server send it ones, but when we check SMTP logs of Ability mail server we can see that mails are realy sended several times to some adreses but to some adreses are sended ones (as must be).
What we can check/change to avoid this problem?

regards
bkova

[Code Crafters]

If SMTP logs show several emails then SQL server or any other mail client source is the one sending too many. You can configure SQL server to send to a mailing list on Ability Mail Server which in turn will send the email to multiple email addresses for reports that are for multiple people to see if that helps or if indeed SQL server is sending out more often than you expect and may be configured wrong.

[bkova]

Hi,
Mails are unique for each client so it can't be send to mailing list.
We checked SQL logs (source of mails) and it's true that SQL server send mails several times (but not all mails). This hapening because they are not confirmed as succesfull sended so SQL repeat it. SQL has set TIME OUT parameter to 300 sec so when he send mail- wait for answer (from Ability) about confirmation of successfully sended mail and if confirmation is not received after 300 sec he send it again (and this repeat 5 times).
This is SQL log when this resending was trigered:
The mail could not be sent to the recipients because of the mail server failure. .... Exception Message: Cannot send mails to mail server. (The operation has timed out).
We found that this problems come in this peak situations and CPU is on 100% so Ability is not response in normal period (maybe also Antivirus kill him during san a lot mails at same time).

To try solve problem we will increase TIME OUT parameter (for example to 2400 sec) but if confirmation still does not come from Ability during this new Time OUT period it will be sended again.

[Code Crafters]

You may need to set the SQL server's IP to be allowed to bypass several systems.

You can add the IP to the SMTP safe relay list to be always allowed to relay without SMTP authentication.
You can add the IP to the SPAM white list to skip SPAM or tick for authenticated users (from step above) to be exempt from SPAM checks.
You can add a content filter rule to skip later rules based on IP.

This should speed up the processing time of these emails if that's the only factor stopping them being delivered.