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I need some help with respect to sendmail configuration.

The basic problem is that I have some employees working from other places and they need access to their mail. So what I have done right now is whatever mails which are meant for them which are generated from within the company and collected by my internal mail server is bounced to an external mail server from where the employees access it. This is done through a email id on a different domain. This was working fine till I restricted the external mailing access for certain users using rulesets in Once I had put that in place only people who had external mailing rights could send mails to people outside the office.

What I would like to know is that is there anyway where I can expose sendmail on two different ips and thereby configure everybody's email id to point to the same internal mail server using 2 different ips. one ip when inside the company and one ip outside the company.

Is it possible that I have one static ip configured for both internal access and external access or is there any otherway it can be done with sendmail.

Can anybody help me

Sorry for the long post

Regards Vinayak

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up vote 1 down vote accepted

I have to echo the comment that you might be making things too complicated, although there's no compelling reason to stop using sendmail if you are comfortable with it. What about just doing a central mail repository accessible to both your inside and outside networks? I've done this with sendmail, dovecot, and squirrelmail on a CentOS server. Set up your squirrelmail to only run over https and then people can securely access their mail in the office or remotely over the web interface. Then use dovecot to provide only imaps for retrieving mail and sendmail with SASL on port 587 to send mail. This works inside or outside your main office, reducing the amount of reconfiguration necessary on individual client machines.

With dovecot & sendmail set up for external access, external users can use a client like thunderbird to retrieve their mail (or alternate with using squirrelmail as needed). Also note you can use self-signed certificates for all of this to keep your costs low.

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+1 for "[...] although there's no compelling reason to stop using sendmail if you are comfortable with it". Although I still believe many things are just way easier to implement with Postfix. – weeheavy Jan 7 '11 at 7:50
thanks for the tip. I am looking for a solution like what was outlined in your answer. The only thing confusing me is that how to expose the ip for both internal mail access and external mail access. Right now every person who access mail remotely has got two sets of profiles for internal and external access. I want to avoid this and have only one profile which they use so that the dependance of users on the it department reduces. I would like to access the mail servers through clients like outlook and thunderbird rather than the web interface so that email creation is done offline also – Vinayak Mahadevan Jan 7 '11 at 11:24
You need the mail server to be available on both internal and external IP addresses. You could for example set up your router to forward the relevant ports (993 & 587) in to your mail machine. Then external users could connect to your router on those ports and actually get connected to your mail machine. Internal users could connect directly to the same ports on the internal IP address of the mail servers. – Phil Hollenback Jan 8 '11 at 8:38

Boah, please just trash sendmail and use Postfix with dovecot to provide IMAP(S)/POP3(S). Your setup seems to be way too complicated for such an easy task.

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Agree with you @Weeheavy i like to add zimbra community version to you post. – Rajat Jan 6 '11 at 9:21
But does zimbra run on centos 5.5 because when I checked up the download page it did not feature centos in the table – Vinayak Mahadevan Jan 6 '11 at 9:39

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