outlook is not recognizing ssl config of zimbra 6.0.2

[fathianf]

Hi,I have upgraded from zimbra 4.5.7 on centos 4.6 (32 bit) to other sever with centos 5.3(64 bit) and then upgraded zimbra 4.5.7 (64 bit) to 6.0.2 (64 bit) and now almost everything is working except outlook ( I have already solved lots of probelm by searching forums). In old server outlook was working with ssl configuration for smtp and pop3 but now outlook (with the same configuration) is receiveing mail but can't send mail and gives the following error.
"The server does not support a SSL connection. Account: 'mail.iut.ac.ir', Server: 'mail.iut.ac.ir', Protocol: SMTP, Server Response: '250 DSN', Port: 25, Secure(SSL): Yes, Server Error: 250, Error Number: 0x800CCC7D"
by the way, on linux workstation with evolution and kmail software every thing is fine.
So please help me how to fix zimbra 6.0.2 so that outlook can send mail with ssl (ofcourse outlook is sending mail without authentication now which I don't like to use it this way as our users have their old configuration with ssl).

[phoenix]

Originally Posted by fathianf

"The server does not support a SSL connection. Account: 'mail.iut.ac.ir', Server: 'mail.iut.ac.ir', Protocol: SMTP, Server Response: '250 DSN', Port: 25, Secure(SSL): Yes, Server Error: 250, Error Number: 0x800CCC7D"

That my, or may not, be a problem. When I check your DNS records from here I find that you have multiple mail servers with the same MX priority that resolve to different IP addresses, this is definitely not a good idea as the user can end up at a different mail server than the one you intended. You need to fix that before you can make a diagnosis of your problem.

[fathianf]

thanks for your quick reply. I changed mx priority for mail.iut.ac.ir to 10, mta.iut.ac.ir (which is on the same server) and others to 15 but outlook still can't send mail.

[phoenix]

You still should not have multiple MX records with the same Priority but ...... that's your choice.

The first thing to mention is that you should not be using Port 25 for outbound mail, you should use Port 587 (which is the correct Submissions port) and it's already available and supports TLS/SSL. You would be better changing your clients to use port 587 for email submission. Do your Windows machines have any form of anti-virus software installed (Avast or Norton) by any chance? If they do then disable them from scanning your inbound/outbound email.

Originally Posted by fathianf

"The server does not support a SSL connection. Account: 'mail.iut.ac.ir', Server: 'mail.iut.ac.ir', Protocol: SMTP, Server Response: '250 DSN', Port: 25, Secure(SSL): Yes, Server Error: 250, Error Number: 0x800CCC7D"

That part of the error message should explain the problem.

[fathianf]

thanks again. I had already working with outlook 2003 and zimbra 4.5.7 with the same configuration untill two week ago before upgrade, with all of these mx records and port 25. Do you mean zimbra 6.0.2 has something different. Also as you said, I change port 25 to 587 in outlook but still get error.
please be patient and let me know what to do.
Thanks in advance for your cooperation.

[phoenix]

Originally Posted by fathianf

thanks again. I had already working with outlook 2003 and zimbra 4.5.7 with the same configuration untill two week ago before upgrade, with all of these mx records and port 25. Do you mean zimbra 6.0.2 has something different. Also as you said, I change port 25 to 587 in outlook but still get error.
please be patient and let me know what to do.
Thanks in advance for your cooperation.

I also asked you about anti-virus software on your Windows machines, do you have any installed and if you do then disable or remove it.

[fathianf]

Hi, after searching on port 587 for tls, I found that outlookis not accepting port 587 and I shold use port 465. So i changed my configuration to use port 465 for smtp on ssl and outlook is working now. Would please let me know if this port is ok to use? because I need to inform our users to change their configurations.