Server email notifications
What kind of server email notifications can I subscribe to and what actions do I need to take?
Log in to the environment of the disk notification.
Navigate to your domain log folder
In this folder you can find the mail.log, because of the logrotate there will be 8 mail.log files.
There are multiple actions we can perform to check why mails are bounced.
The easiest way is to
cat the mail.log and grep on the bounced mails.
This will print all of the bounced mails and give information why there are bounced.
cat mail.log | grep 'bounced'
Most of the bounced output logs will be email account does not exist or Quota exceeded.
To solve this problem check if your website uses captcha on the create account and subscribe to newsletter.
Sep 6 11:56:02 production834 postfix/smtp: A436C2602C4: to=<email@example.com>, relay=aspmx.l.google.com[2a00:1450:400c:c0a::1b]:25, delay=0.23, delays=0.01/0.01/0.18/0.03, dsn=5.1.1, status=bounced (host aspmx.l.google.com[2a00:1450:400c:c0a::1b] said: 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 g5si8026791wma.48 - gsmtp (in reply to RCPT TO command))
Sep 5 21:20:37 production521 postfix/smtp: 0D22E2C21AD7: to=<firstname.lastname@example.org>, relay=freemx2.spammail.spam.com.cn[18.104.22.168]:25, delay=3.5, delays=0/0/2.7/0.76, dsn=5.2.1, status=bounced (host freemx2.spammail.spam.com.cn[22.214.171.124] said: 552 5.2.1 Quota exceeded or service disabled. (in reply to RCPT TO command))