Email problems

[Endgame]

A lot of my emails aren't getting to their destination and i am getting them sent back to me saying that they haven't been delivered.

I am using Outlook Express and the message i get is:

This message has not been delivered after 72 hours.
Therefore it is being returned to you.

[Ann]

That usually means a problem their end.  Are they all going to the same server?

[Simon]

What Ann said. 

[Endgame]

That usually means a problem their end.  Are they all going to the same server?

No they have been sent to different people

I have just had an email from a friend who said he has just rceived an email today that i sent on Wednesday

[Ann]

If he looks in the headers he will be able to see where it was held up.  That'll tell whether it's your fault or his.

[Rik]

What everyone's said, EG. The message you have received comes from the system as an advisory that it can't reach the destination server. If you drop support an email with the affected addresses, they'll be able to check whether there's a routing problem, but it could be a remote server issue or even a boundary server, which protects against spam by asking for the message to be resent. If they have set it up with the value too high, the email keeps bouncing off it.