Email not working

[tds]

I've tried to send emails out on different accounts (same shared hosting account, but different domains and therefore mail servers), and some are failing.

My main account domain fails to send, says it recieves fine (although I haven't received any emails this morning - which is very uncommon).

Webmail is working fine.

I can send test emails to myself through different domain accounts (again, same hosting account), some send fine, but no emails ever arrive. Got 1 undeliverable message:

The following recipient(s) could not be reached:
????? on 25/05/2006 08:52
503 valid RCPT command must precede DATA

I get the following message in Outlook 2003 when sending emails:
Task ... reported error (0x800CCC92) : 'Your e-mail server rejected your login. Verify your user name and password in your account properties.

I've tried ports 25 and 26 for smtp. I already have it set to SMTP requires authentication, and have tried use same settings as incoming and specifying log on details.

I've been to dnsreport.com and got this:
???.com. - 70.84.231.2 [Could not connect: Got an unknown RCPT TO response: 550-Verification failed for <TestedFrom-195.137.105.112@DNSreport.com>
550-unrouteable mail domain "dnsreport.com"
550 Sender verify failedHaven't a clue what that means!

I've tried changing my password, but as mentioned webmail works fine.

I notice that Hostgator have been changing email/webmail lately, could that be why it's down?

[tds]

EDIT: Although I thought the following solved the problem, it just meant that Outlook didn't complain. Basically the mail server is no longer responding, sent emails aren't being recieved and anyone email my accounts get's a bounce back error!

What I tried and thought solved the problem...

Went to post a support ticket, and hostgators superb ticket system, automatically read my email and pointed me in this direction...

If you can receive mail but aren't able to send this means one thing.....

Your internet provider is blocking you from using anyone's outgoing mail servers but their own. Many major ISP's are blocking outgoing emails. The reason they do this is to prevent you from using their internet connection for spamming purposes. You will still be able to send emails, but only by using your ISP'S outgoing mail server. Every ISP's outgoing mail address is different, but for the most part they will be mail.yourispname.com For example, if you had hosting with AOL.com, their outgoing mail server would look like this: mail.aol.com If mail.yourisp.com does not work and you are still unable to send emails, you will need to call your internet service provider to find out what their outgoing mail server is.

We also have exim running on port 26 for this very reason. A possible work around is to change your outgoing mail to port 26.

EDIT: I thought that the ISP had changed their system r.e. the above, but it isn't the problem.

[tds]

EDIT: So Outlook now doesn't complain when I send emails, but I still can't receive. And on webmail, my inboxes are empty. If I send through webmail the recipient doesn't recieve anything and nothing is coming into the mailbox.

So where are my emails going?

I think my mail server is down, but surely this would mean everyone on that mail server is down?!?

Any ideas appreciated?

Peter

[tds]

As always, Host Gator support sorted out the problem, alas they didn't explain how it happened, but they sorted it non the less.