23.1. Setting up email

Even for dynamic IP numbers, you can certainly configure sendmail on your machine to send out any email that you compose locally. Configuration of sendmail can be obscure and difficult - so this document does not attempt to tell you how to do this. However, you should probably configure sendmail so that your Internet service provider is designated as your "smart relay" host (the sendmail.cf DS option). (For more sendmail configuration info, see the sendmail documents - and look at the m4 configurations that come with sendmail. There is almost certain to be one there that will meet your needs).

There are also excellent books on Sendmail (notably the 'bible' from O'Reilly and Associates), but these are almost certainly overkill for most users!

Once you have sendmail configured, you will probably want to have sendmail dispatch any messages that have been sitting in the outbound mail queue as soon as the PPP connection comes up. To do this, add the command

sendmail -q &

to your /etc/ppp/ip-up script (see below).

Inbound email is a problem for dynamic IP numbers. The way to handle this is to:-

• configure your mail user agent so that all mail is sent out with a "reply to" header giving your email address at your Internet Service provider. If you can, you should also set your FROM address to be your email address at your ISP as well.

• use the popclient, fetchmail programs to retrieve your email from your service provider. Alternatively, if your ISP is using IMAP, use an IMAP enabled mail user agent, (such as pine).

You can automate this process at dial up time by putting the necessary commands in the /etc/ppp/ip-up script (see below).