Not sure if this has been made clear with all the chatter which has gone on.

Orange, like many other ISPs world wide block port 25 except for their own mail servers.

This is an attempt to minimise non traceable use of their mail servers.

In reply to a post by Mike_Williams:

Orange, like many other ISPs world wide block port 25 except for their own mail servers.

But TT doesn't. Not sure about Vodafone. The 2 outside ISPs with which OP tried to use Orange's port 25 SMTP.

He did not try to use someone else's port 25 while connected to Orange.

Edited by XRaySpeX (Sun 27-Jan-13 21:58:00)

In reply to a post by XRaySpeX:

In reply to a post by Mike_Williams:

Orange, like many other ISPs world wide block port 25 except for their own mail servers.

But TT doesn't. Not sure about Vodafone. The 2 outside ISPs with which OP tried to use Orange's port 25 SMTP.

He did not try to use someone else's port 25 while connected to Orange.

But TT doesn't.

Wow, I am very surprised that TT don't block port 25.

In reply to a post by Mike_Williams:

Wow, I am very surprised that TT don't block port 25.

Yes, I'm going by this for TT:

In reference to www.talktalk.co.uk/legal/broadband-traffic-management/:

Are any services, content, applications or protocols always blocked on this product?**
If so what? NO

compared with Orange:

In reference to help.orange.co.uk/orangeuk/com.instranet.InstraServlet?Command=com....:

Are any services, content, applications or protocols always blocked on this product?** Yes
If so what?
The only restriction we�ve put in place is an email setting that helps protect our customers against unsolicited emails, also known as spam.
(For the techies amongst you this means we stop connections to non-Orange SMTP servers on port 25, and block NetBIOS)

In reply to a post by Mike_Williams:

Wow, I am very surprised that TT don't block port 25.

Sky don't block port 25 outgoing either.

In reply to a post by Mike_Williams:

Not sure if this has been made clear with all the chatter which has gone on.

Orange, like many other ISPs world wide block port 25 except for their own mail servers.

This is an attempt to minimise non traceable use of their mail servers.

My experience has been that port 25 is/has been acceptable provided authentication was used. But it is a changing situation that it is making it difficult, but not impossible, to find a common configuration that will work irrespective if you are using your ISPs SMTP server or connected elsewhere.

What is wrong with Port 587 authenticated but SSL OFF?

In reply to a post by XRaySpeX:

What is wrong with Port 587 authenticated but SSL OFF?

All depends on whether the OP's external (to ISP) mail server will accept traffic on port 587

In reply to a post by XRaySpeX:

What is wrong with Port 587 authenticated but SSL OFF?

None that I am aware of. That's what I use for this ISP.

I have working solutions for a few ISPs where it is possible to use the identical settings in Microsoft Office 2010 to use the ISPs SMTP server whether connected to their network or visiting another. The added conplexity is using my own domain name which often requires using strange configuration features found in that software..

As an aside, I found BT to be particularly helpful in trying to achieve this aim but their appears to be no solution. However they could offer to meet my desires through unwanted cloud based services.

Most ISPs block port 25 at most, as per that Orange quote.

Note: We are only talking here where Orange is the home ISP, where port 587 is appropriate home & away. Other home ISPs may need a diff port or not have one at all.