I have been browsing this forum in search of a solution or possibly a similar issue for several days already but to no avail. My problem is as follows:
I have installed Virtualmin using the install script on a fresh Centos 5.3 copy. I used to have some problems with DNS but those are solved already. Right now the only problem I have is that I cannot send mails using Outlook. I am using Postfix. I am 100% sure that my ISP is not blocking port 25 (I have contacted them + canyouseeme.org reports a service available on port 25). I have tried telnet localhost 25 from my server console and it works flawlessly, whereas telnet mydomain.com 25 from a remote PC times out. The funniest thing is that http://centralops.net/co/DomainDossier.aspx shows that there is SMTP service available on port 25. Outlook gives the following output: The connection to the server has failed. Account: 'mail.mydomain.com', Server: 'mail.mydomain.com', Protocol: SMTP, Port: 25, Secure(SSL): No, Socket Error: 10060, Error Number: 0x800CCC0E . Everything else: IMAP/POP3, sending mails through Usermin, receiving mails in outlook etc. works fine. If I run SMTP on any other port except 25 (ie 2525 or 26) it also runs smoothly. Any ideas will be appreciated.