This problem suddenly occured I can receive E:Mails no problem but not send.
The Microsoft Test Message is sent and received OK in Both. I can send to myself.
But when I try to send to others I get it returned from the System Adminstrator with the following message :--Relaying not allowed - please use SMTP AUTH'

Has anyone any ideas please ?

Thanks in advance

Welcome to the forums.

How do you get your emails? Are you using exchange, pop3 or IMAP?

If it's POP3 or IMAP who's your ISP.

Are you using a machine inside a company network and trying to access your personal mails? (Also check that you have the correct SMTP server set up.)

It could be that Outlook is trying to use the next available SMTP server on the network and using that to send emails under a different domain (E.g. you are sending a mail from me@mydomain.net and you are on a company network which is set up for me@company.com) and the server is configured to refuse other domains being sent over the server.

RE:Mail is POP3 ISP is o2

Not works system this is on home PC

Have checked that all is set up correctly just as it always has been for the past 10 years. Also had it checked by 2 Computer Engineers and 1 Software Programmer. And they don't know.
Have uninstalled and re-installed 2/3 times but to no avail.

How does the SMTP server expect to be treated?

I know some ISPs require you to use "POP before SMTP" authentication - i.e. you need to tell Outlook, under the SMTP options, that it needs to poll the POP server, before it tries to send email over SMTP. Otherwise, have you set up your SMTP authentication correctly, in accordance with O2s requirements? Their website should have a guide to setting up mail clients, which should tell you which authentication method it requires.

I do know what is required and I do not like the inference that I do not.
Microsoft Outlook both in 2003 and 2010 Beta is set up correctly exactly as informed by o2 exactly the way I have set it up for many many many many years.
So please do not ridicule.
It is solution I want

Dave is a particuarly experienced and helpful member of this forum, and he was not ridiculing you or implying anything. What you inferred is up to you, but I very much doubt any of it was meant.

Clearly something is not right, as you can't send e-mail. Dave was suggesting a number of areas where it is most likely to be, and double-checking a number of things. If we all had to post with a guaranteed solution without asking for further information or testing the basics first nothing would get answered around here, especially given the quality of some of the questions!

Pfft.

Take a running jump mate.

Please show where Dave has ridiculed you?

I was fully aware what he ment but he had read all my remarks he would have been aware that the correctness of setting up was correct and had been checked by outsiders (knowledgeable people) 3 times. It is sometimes that the lesser knowleable come up with the answers.
No offence was ment or given.

Are you using O2's SMTP servers & registered your what your domain name is with O2?
Have you ticked the box to say your server requires authentication? (although Dave's asked this already)

A lot of ISP's stopped users with their own domains using their own smtp servers to cut down on spammers, sounds like O2 are one of them.
You may need to change your smtpo server to O2's and put in your O2 username & password for it to work.

Could you post the text of the bounce here (or PM it to me)? I can usually work it out from the bounce message.

I'm with o2 and have my own domain which uses it's own SMTP server....the one provided by my host. Works fine.

Is the Secure Password Authentication box ticked?

This is the latest I've had from o2, I've used o2 for a long while nolw and never had to do this. To be honest I don't think the man knows what he is talking about. """"If you're running your own mail server or have a domain hosted by a third party company and you need to use port 25 for communication. Then there is a solution as you'll be unable to use the smtp.o2.co.uk server.

On your email client you'll need the following settings for the outgoing
server:

Outgoing Server : 87.194.0.68
User Name : your email address
Password : the password you use to login

Another method is to change your email client port to port 587 and the port on the server you are using to port 587 also.""""

Any Comments.

By the way it don't work

Sorry been away for a couple of days

No the Password Authentication Box is not ticked.

What is the domain name you're trying to send email from?