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Topic: SMTP Send & Recieve on Port 465

How would I go about configuring iRedMail to only use port 465 to receive and transmit emails for the SMTP server?

The reason for this, port 25 is blocked for inbound and outbound communication from my ISP.

Cheers,

MFiendD

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Re: SMTP Send & Recieve on Port 465

You will not be able to receive mail on port 465 directly, as far as I know, because no other mail server will try to send mail to your server on this port (it's used for SSL/TLS only).

You will also (most probably) not be able to transmit mail on port 465 directly, because most server will probably only accept SSL/TLS authenticated users on that port.

The solution would be to ask your provider in what conditions they would open port 25 for you. Most of them would open port 25 if they know you have a mail server, which is not open relay and so on.

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Re: SMTP Send & Recieve on Port 465

I can answer this question myself and I should know better given my background within Information Technology.

I'm new to mail servers so forgive my ignorance. After further research I have found that I can configure a smarthost such as Gmail or my ISPs mail server using port 465 or 587 to send email out to the world. In order to do this you must have an account with your smarthost to initiate the connection from your server to the smarthost's server using TLS and AUTH.

I have tested my ISP as a smarthost with using port 25 (Standard SMTP port) to my ISP and it works just fine. There is more work involved to configure Gmail as a smarthost which you can do by following the guide at http://behindmyscreen.newsvine.com/_new … easy-steps .

As for receiving all mail on port 465 it would be impossible as all mail servers sending mail to my server would need to initiate a connection using TLS which requires AUTH to my server. This defeats how SMTP works. I was thinking of security and having all transmissions encrypted and not thinking how SMTP works. So for this I issue myself the ID10T award. The only way to use 465 or 587 would be the scenario of sending and receiving email between accounts within the same domain.

If my understanding is wrong please feel free to correct me as I stated above I'm new to mail servers.

Cheers,

MFiendD


Terminology:
TLS is an SSL (Secure Sockets Layer) connection from one host to another in order to encrypt communication between each other.
AUTH = authentication which requires a user-name and password to initiate a connection.
Smarthost = mail server acting as a relay to send mail from your server to the world

4 (edited by mfiendd 2010-02-15 17:31:38)

Re: SMTP Send & Recieve on Port 465

Wow maxie_ro,

I was writing my reply to answer my own question when you posted. Thank you for you post as what you said is exactly what I understood after learning more about SMTP.

I was fixated on one thing, encryption. I wasn't thinking of the big picture. I really should have known better as I deploy websites and application servers a lot which require SMTP as a relay to send messages.

I'm beating myself up over this. It's beer o'clock.

Cheers,

MFienDD