Vtrio SysAdmins

In cpanel exim mail logs are stored in following files

/var/log/exim_mainlog -: All the logs are recorded into the exim_mainlog file
/var/log/exim_rejectlog -: Rejected emails logs are recorded into the exim_rejectlog
/var/log/exim_paniclog -: If the exim server stuck or fails then those logs will be recorded into the exim_paniclog file.

Log line flags:
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<= Shows arrival of a message for incoming mail.
=> Shows a normal message delivery for outgoing mail
-> Shows additional address for the same delivery, i.e. an Email forwarder.
*> Shows delivery suppressed by -N**delivery failed; address bounced.
== Shows delivery deferred; temporary problem.
** Shows delivery failed; address bounced.
From the email queue, we can find the log details of an email by using the command “exim -Mvl Message-ID”

A summary of the field identifiers that are used in log lines:

R=  The address immediately following “<=” is the sender address. A bounce message is shown with the sender address “<>”, and if it is locally     generated, this is followed by an item of the form R=<message id>.

T= The relay used to transmit the message. Example: T=remote_smtp T=local_delivery

H= Represents the host name and IP address.

U= The MTA used.

I= local interface used.

P= This is the return path on delivery.

A= If A= is present, then SMTP AUTH was used for the delivery.

S= Is the delivery size of the message.

ID= Represents the incoming message ID

T= Topic / Subject

from :From whom the mail was received

for : Who the email is for.

C : SMTP confirmation on delivery.

D : Duration of “no mail in SMTP session”.

S : size of message.

X :TLS cipher suite

DT:on => lines: time taken for a delivery

Email of users are stored in “/home/user/mail/<domain>/<emailuser>”
/home/username/mail(mail folder)
/home/username/etc (configuration files)
/domain.com
maildirsize (quota/usage summary, expendable)
cur (default inbox for read email)
new (default email for unread email)

In order to send the mails the website and email for a domain need not be in same server. DNS is used to point the services to the correct place. Exim, cPanel SMTP service needs a little help beyond DNS in order to know how to handle mail that is generated locally. This is where /etc/localdomains and /etc/remotedomains are usefull.

/etc/localdomains :

If the MX record of the domain is pointed to same server then there must be entry for that domain under /etc/localdomains file for local delivery of email.

/etc/remotedomains :

If you are using remote mail server then entry for that domain must be removed from /etc/localdomains files and should added in /etc/remotedomains files for proper routing of emails.

Setting this option during account creation
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Local Mail Exchanger:-cPanel will place the domain in localdomains.

Remote Mail Exchanger :- It will place the domain in remotedomains.

Backup Mail Exchanger:- The domain will be added to localdomains but will only accept mail if there are no other mail servers available.

Automatically Detect Configuration:- It will check the DNS Mail Exchanger records to see where the DNS is pointed, and make the configuration based off of that.

Changing the exchanger after account creation in WHM
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In WHM, navigate to “Edit MX Entry” under “DNS Functions” in the left menu list.

From there, simply select the domain name you wish to edit, and then select the desired mail exchanger (Local Mail Exchanger, Backup Mail Exchanger, or Remote Mail Exchanger) to change the mail routing settings for the domain:

Changing the exchanger after account creation via SSH
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Modifying a domain to use a different exchanger is as simple as SSHing into the server and editing the files; simply remove the domain from one file and add it to the other. It is that simple. No need to restart services afterward.

How to change sites MX record to point mail to another domain or server.
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An MX Record is used by a mail server to route incoming email. Changing your MX record is usually done to redirect email to a remote server.

To point the MX to another domain do the following.

1. Log into your WHM.
2. Click the Edit DNS Zone.
3. Select the domain name from the drop-down list.
4. Change the MX from domain.com to mail.domain.com.
5. Click the save button.

If you want to point it to another server using the same domain:

1. Log into your WHM.
2. Click the Edit DNS Zone.
3. Pick the domain you wish to edit.
4. Change the MX from domain.com to mail.domain.com.
5. mail.domain.com should have the A entry of the external mail server IP address.
6. Click the save button.

Note: You need to change the domain from /etc/localdomains to /etc/remotedomains for sending mails when your mail service is hosted on another server.