We have a upcoming task of Migrating our Production mail server to a new environment. Mail Server is sendmail and OS is RHEL 3.


We are planning to migrate on RHEL 6 with the latest version of Sendmail

Few issues I am seeing is sendmail.mc does not exist on current mail server, only sendmail.cf exist.

I need clarifications on the following below points...

1.Not sure whether it is possible to generate sendmail.mc from sendmail.cf. In that case I could have tried to enable existing sendmail.mc settings in new mail server thus migrating to RHEL 6 .

  1. Can copy existing sendmail.cf to new mail server and restart sendmail . But this may lead to issues like deprecated configuration items and version mismatch.

  2. Generating sendmail.cf in new mail server from existing sendmail.cf will be tough as this file is difficult to understand and not recommended.

Also any other suggestions to migrate to latest mailserver based on sendmail.mc missing on current scenario.

  1. Now since we are planning to migrate to RHEL 6, we are not sure how to generate sendmail.cf file as sendmail.mc does not exist on current mail server. We can copy sendmail.cf from existing mail server but there will be version mismatch issue or may be some configuration items has been deprecated.

  • Please add the sendmail.mc to this question. Aug 19 '16 at 15:53
  • That is the whole issue. Sendmail.mc is missing
    – Zama Ques
    Aug 19 '16 at 16:37
  • My fault then, I understood sendmail.mc was present in the legacy server. In the old days of yore, many sysadmins edited direct sendmail.cf...I do not recommend it. I have not used RH for quite a while, would you verify if the source package brings the default mc? Aug 19 '16 at 17:51

The sendmail.mc is an m4 macro source file that when processed generates your sendmail.cf. It is normally not possible to generate in an automatic way a sendmail.mc from a sendmail.mc.

Whilst the sendmail.mc file in the legacy system was the source of the sendmail.cfthat is present there, you have to double check whether there were posterior editions to sendmail.cf directly, as some less experienced system admins frequently did. If that is not the case, read on.

If sendmail.mcor sendmail.cf were never customized, and are the default from the distro, it could also be a safe be to use the new one as it is (highly doubtful, but must be said).

Otherwise, if sendmail.cf was never touched directly, and all work was done in top of the sendmail.mc, the original sendmail.mc can be used to generate a sendmail.cf in the destination system with minimal, or none changes with the command:

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

To get to the point, it is highly doubtful the old sendmail.cf will work, as it will be obsolete; however sendmail.mc is a macro file, are there is a fairly chance it will compile cleanly; even if not, it can surely be used as the basis for the new config if it was used in the first place for producing the whole configuring.

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