Some command to check and trouble shoot sendmail

Check send mail version:

#/usr/sbin/sendmail -d0.13 </dev/null

Kill Sendmail

#killall -HUP sendmail

Check network status of sendmail:

#netstat -tuplan | grep sendmail

#  netstat -lnptu

#netstat -tulpn | grep :53

Check Sendmail routing:

#echo “3,0 info@cadena-it.com” | sendmail -bt

#echo “3,0 phongb2b@outlook.com” | sendmail -bt

# sendmail -bv phongb2b@hotmail.com

Checking Spam filter process:

#ps -aux | grep spam

Checking clamav process:

#ps -aux | grep clamav

How to view and manage sendmail SMTP queue:

  • Listing all e-mails stored in Sendmail queue:

#sendmail -bp

Or

#mailq

  • Checking queue for specific mail sender or recipient:

# mailq | grep -i email@domain-name.com -A 2 -B 2

  • Removing all e-mails from Sendmail queue:

# rm /var/spool/mqueue/*.*

#rm /var/mqueue/*.*

Deleting all pending mails from queue:

# sendmail -qS -v domain-name.com

To delete e-mail from certain user or recipieint:

# sendmail -qR -v someone@somedomain.com