Errors sending to Hotmail from ASP app...

[Forza]

I have a website where people can register etc and I send them a confimation email. The problem I'm finding, is 1 in 4 people who use hotmail seem to fail. Am getting this:


The following recipient(s) could not be reached:

********@hotmail.com on 29/10/2005 22:50
The e-mail system was unable to deliver the message, but did not report a specific reason. Check the address and try again. If it still fails, contact your system administrator.
<******** #5.0.0 smtp;550 Requested action not taken: mailbox unavailable>


what's that a symptom of ? Some hotmail accounts get through just fine so I don't think it's a system-wide block.

Ideas?
:confused:

[Bibofa]

Anyone have an ideas ?

[counterbalanced]

I've been having problems today and yesterday sending to hotmail. The mail servers seem not to be responding.

Just moved to a new server this weekend, so thought the problem was my configuration, but yahoo and gmail and some others seem OK.

I read about some hotmail problems over the last few days, does anyone know if they are still occuring?

[J.D.]

This error (550) indicates that your SMTP client got through to the front-line SMTP server, but the server rejected the name of the mailbox. This could be simply because the mailbox doesn't exist or it could be that access to this mailbox is restricted for security reasons to your client. For example, if there was enough spam coming from your IP address or address range, you may get this kind of response. Also, keep in mind that hotmail.com uses SPF (see 18405 for details) and this could be caused if your SPF record is misconfigured.

J.D.

[Forza]

OK... update:

After looking @ J.Ds thread, I tried DNSReport and punched in the hotmail address that was failing and it came up with:

mx1.hotmail.com. - 65.54.166.99 [Could not connect: Got an unknown RCPT TO response: 550 Requested action not taken: mailbox unavailable
]
mx1.hotmail.com. - 64.4.50.99 [Could not connect: Got an unknown RCPT TO response: 550 Requested action not taken: mailbox unavailable
]
mx1.hotmail.com. - 65.54.252.99 [Could not connect: Got an unknown RCPT TO response: 550 Requested action not taken: mailbox unavailable


Weirder and weirder.

[counterbalanced]

I can't even get an error back from their mailservers:

telnet 65.54.166.99 25
Connecting To 65.54.166.99...Could not open connection to the host, on port 25: Connect failed

Any ideas. Could this be caused by a missing PTR record on my server?

Forza what happens if you try to telnet to one of the hotmail servers from your machine?

Looking at the logs, some mails to hotmail are getting through but most are not.

[Forza]

I can telnet ok, but when I get to the RCPT stage I get the 550 error.

Very annoying.

[J.D.]

I can't even get an error back from their mailservers:

telnet 65.54.166.99 25
Connecting To 65.54.166.99...Could not open connection to the host, on port 25: Connect failed

Any ideas. Could this be caused by a missing PTR record on my server?

Forza what happens if you try to telnet to one of the hotmail servers from your machine?

Looking at the logs, some mails to hotmail are getting through but most are not.Not being able to connect to an IP adderss has nothing to do with DNS - it's either their server is down or your IP range blocked. Since their server isn't down (I can connect to it just fine), your IP adderss or range is being blocked. It happens quite often that a block of IP addresses is blocked (e.g. if they recorded some spamming activities from an IP address in this block) and your address just happens to be among them. Another possibility is that if you are trying to connect to the SMTP server from an IP range allocated to an ISP (e.g. cable or DSL) - many administrators block these ranges as well simply because too much spam originates from cable/DSL users.

J.D.