Sendmail is only accepting connections from localhost

By default configured to accept connection from local system (127.0.0.1). This should avoid open mail relay problem.

To allow connections from ALL hosts/LAN IPs open sendmail.mc file (login as the root):

# vi /etc/mail/sendmail.mc

Look for line that read as follows:

DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl

Comment or remove above line and insert new line that read as follows:

DAEMON_OPTIONS(`Port=smtp,Name=MTA')dnl

Above line will force to accept connection from any host. Save the file. Regenerate sendmail configuration file using m4:

# m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf

If this command is resulting by giving such of error as below, this means that the file

/etc/mail/sendmail.mc:10: m4: cannot open `/usr/share/sendmail-cf/m4/cf.m4': No such file or directory

Then, this means that the sendmail.cf.xx rpm package is missing and require to be installed.

In my case, I had to mount the cdrom, and look for this rpm file:

sendmail-cf-8.13.8-2.el5.i386.rpm

Restart sendmail service :

# /etc/init.d/sendmail restart

Domino hiding SMTP header items

I needed to hide server version and Domino information ‘leakage’ in MIME information, follow the steps below to hide this information.

To hide the senders client information which is ¬†Lotus Notes 6.5.3 as indicated by the X-Mailer line, then you would include the field “$XMailer” as one to be hidden from the SMTP header. Also, the X-MIMETrack field above shows information about all the SMTP servers that have itemized and serialized the SMTP message on it’s travels to my IBM account. Hiding the $MIMETrack ¬†will force the outbound Domino server to not include any information about the serialization and itemization when it leaves Domino. Finally specifying the Received field will remove information in the Received field of the message about previous hops that the message has taken in your internal system.

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