What about it?

I already told you that TELNET to it failed, whereas TELNET to UCLMail SMTP, where I am also unauthorised, connected OK.

Please expand your cryptic remarks to something more communicative.

Sorry, I don't understand what you mean

Turning to the laptops used at various homes, the ISP is not BT in every case. The POP3 and SMTP is set up as the office desktops but in addition authentication is required for SMTP. This information is provided by BT once you have established your credentials and made changes to the CNAME records. Carry out everything to the letter and everything works fine no matter where you go except in the office where you quickly discover you can't send out emails unless the authentication details are removed.

To me it's quite illogical and frustrating that the settings can't remain the same for the office and at home so my solution was to use the hosting provider's SMTP settings, but them we hit the poor reputation problem.

Home ISP blocking port 25 doesn't seem to be a problem in this case.

In reply to a post by RobertoS:

Home ISP blocking port 25 doesn't seem to be a problem in this case.

Sorry, OP's description make it difficult, for me at least, to see the wood for the tress and identify the actual issue he has.

As I see it, his firm has a # of homeworkers, who live in diff homes and are supplied by a raft of ISPs. Surely, by the law of averages, some of these ISPs will block all foreign port 25 SMTPs, thereby nullifying the use of any port 25 BT SMTP, whether authenticated or not. For example, any homeworker using O2 or Orange, amongst others, as ISP would not be able to to use the BT SMTP both at home and in the office.

Therefore, my solution, applied individually for each homeworker, will work in all cases w/out any need to re-configure anything once it has been set.

While your solution is a good one and will work, you are ignoring 2 things the OP said:
1. It works at home but not in the office.
2. It should work in both without changing any settings.

It seems that BT Business are migrating the email over to Office 365 and the new mail server is smtp.outlook.com. It may be that the OP problems are due to this migration.

In reply to a post by BatBoy:

you are ignoring 2 things the OP said:
1. It works at home but not in the office.

That's cuz he set up only 1 mail client a/c configured for Home. Had he set it up configured for Office, it would not have worked at Home. His problem cannot be resolved with just 1 a/c.

In reply to a post by BatBoy:

2. It should work in both without changing any settings.

My solution does just that; that's its whole point!

The only mention of port 587 SMTP, that you proposed, on the official BT site were in conjunction with Office 365 wherever it stated:

Note: These settings only apply to Microsoft Office 365 customers.

In reply to a post by XRaySpeX:

In reply to a post by BatBoy:

you are ignoring 2 things the OP said:
1. It works at home but not in the office.

That's cuz he set up only 1 mail client a/c configured for Home. Had he set it up configured for Office, it would not have worked at Home. His problem cannot be resolved with just 1 a/c.

It can, by using auth-smtp

In reply to a post by BatBoy:

2. It should work in both without changing any settings.

My solution does just that; that's its whole point!

Having 2 accounts is changing settings

Problem solved!

In reply to a post by BatBoy:

It's easy to confirm: telnet mail.btconnect.com 587

You confused the wrong server with that port.

It's 'telnet smtp.outlook.com 587' that connects OK. All to do with Microsoft Office 365.

Out of curiosity, what is "auth-smtp"? Please spell it out and don't just say authenticated SMTP, cuz that is what he is using.

http://bit.ly/Mm37sg