Outbound Email problem

[Vivek Kumar]

Hi all,

Recently I encountered a strange problem though its very common, 2 users
sent mail to 2 different blackberry user's account. The blackberry user
said that he got mail after 3-4 hours delay. He was mad at it and said
that our server has some problem as both his blackberry have account
through different phone companies so its not possible that both the
account will receive mails with lot of delay. 
I checked my server and saw that all the mails going out are relayed as
soon as it gets on my server. I tried to send message today to his
blackberry and he got it immediately. Now what could be the problem last
night. I want to dig into it as he wants to know the problem. Can you
suggest where I should start. I checked my server and things look OK to
me.

Thanks.. Any help in this regard will be appreciated.

VK