Delays sending email

[#1]

Are there any known problems with queuing outgoing email?
Received this message on OH email early this morning:
This message was created automatically by mail delivery software.
A message that you sent has not yet been delivered to one or more of its recipients after more than 24 hours on the queue on ptb-relay02.plus.net.
The message identifier is:    1IOuZh-0002bP-8x
The subject of the message is: RE: I found your profile on Ancestry - requesting more information
The date of the message is:    Sat, 25 Aug 2007 13:17:04 +0100
The address to which the message has not yet been delivered is:
  cb3108451.v7d2azlgbpicc3@cbreply.myfamily.com
    Delay reason: Connection reset by peer:
    mta.myfamily.com [66.43.23.60]
No action is required on your part. Delivery attempts will continue for some time, and this warning may be repeated at intervals if the message remains undelivered. Eventually the mail delivery software will give up, and when that happens, the message will be returned to you.

[#2]

That doesnt indicate general delays at PlusNet's end, but it means that the relay servers are experiencing problems communicating with the incoming mail server (mta.myfamily.com) of the recipient.
As it says, it will continue trying, and after a few days will bounce the message to you if still no luck.  It could be the remote mail server rejecting the connection from relay for some reason (perhaps a spam blacklist?) but it's not giving that reason where it would normally reject the connection with an error code and explanation.