If the issue reoccurs or if there is any future difficulty with e-mail forwarding or general e-mail sending and delivery attempts, please check the Exim mail server log to see both prior SMTP activity as well as to monitor current SMTP activity as it is happening. Some examples of the data Exim will log include both locally-delivered e-mails in addition to forwarded e-mails and also bounced messages and related errors. Viewing the log data will help to determine where the issue might be and will help verify if the recipient mail sever accepted the e-mail or not. It is possible that the (forwarded) e-mail may be accepted by the recipient's mail server but held in a queue pending delivery at a later time or after additional processing; this also depends on the recipient's mail server configuration and applicable Spam or other filtering criteria used by the third-party mail service (e.g., Gmail).
Here is the Exim log file path:
Code:
/var/log/exim_mainlog
Here is a command that can be used to safely view the file via root SSH access:
Code:
# less /var/log/exim_mainlog
Here is a command that can be used to monitor for new log messages, such as before and during any testing of e-mail forwarders; new log output will be displayed on-screen:
Code:
# tail -fvn0 /var/log/exim_mainlog