Re: agoodall Re: [OT] Double Messages

On  4-Apr-01 at 06:43, Mike.Elliott@bull.co.uk (Mike.Elliott@bull.co.uk)
wrote:
> Allan (and anyone else bither by this),
> 
> No, its probably not your canada.com account. Its just a quirk of the
way
> that email messages are transmitted across the Internet. Occasionally
> message packets will get routed teo (or more) different ways. When
this
> happens, because of the different delays in each route (goodness knows
how
> many routers and intermediate MTAs a message will pass thro) then the
> message ends up getting duplicated. Its something we all just have to
put
> up with. Happily it does'nt happen too often.
> 
> Mike

Not to be a wet blanket, but packets _may_ be routed two ways, but
the whole message will end up on the server in one block.  See,
each TCP packet has a sequence number, if you get two with the same
sequence number you throw one away.  If you are getting two e-mail
messages some machine has generated it twice.

Roger

(Unix Sysadmin, State of Florida, worked with the states WAN for