[imp] Horde (IMP) email problems

[Andy Dorman]

On 05/08/2014 03:25 PM, Louis-Philippe Allard wrote:
>>> 550 OU-002 (COL0-MC6-F27) Unfortunately, messages from XX.XX.XX.XX
>>>weren't sent. Please contact your Internet service provider since part of
>>>their network is on our block list. You can also refer your provider to
>>>http://mail.live.com/mail/troubleshooting.aspx#errors.

Hotmail (mail.live.com) tells you all about it in the error message you 
provided above.  For whatever reason, they (Hotmail) are blocking/not 
accepting email from the IP address block that your IP is in.

A lot of overly simplistic spam filters try to solve the problem of spam 
by just refusing to accept email from whole swaths of IP addresses. 
These are often dynamic IP addresses assigned to residential users.

It is likely that another residential user with an IP from your ISP has 
an infected PC that is spewing spam and/or viruses and Hotmail has just 
blocked a bunch of IPs on either side of the offending IP and you have 
been caught in the same net block.

You may be able to send your outgoing email through your ISP's smtp 
server.  You can check on this when you contact them to explain that 
their IPs are blocked and can they contact Hotmail to get them 
unblocked.  Of course then they may tell you you should not be sending 
email out from a dynamic IP and that is when you ask them how to relay 
your email out through their smtp server.

Good luck.

-- 
Andy Dorman