Any ideas on how to run multiple fetchmail sessions? Why does the lockfile prevent you from doing that anyway?

I have a scenario where I poll my internet mailserver every four minutes for mail 24/7. The mail downloads to the local mailserver from where people check mail on the LAN. This keeps the flow of mail smooth and prevents network jams every morning when 15 people start to download the whole night's mail together from the internet server.

However, what can happen now is that there could be one very large file, say 10 MB or so - which could take quite a while to download. Until that completes, the next user's mail isn't polled on the internet mailserver. That causes a bottle neck which I'd like to avoid.

I was thinking maybe I could start multiple fetchmail sessions - one for every user - so that if there was a large mail, it would download slowly for the respective user, without blocking essential mail for the other users.

Or is there a better way?

how long does it take to bring in the 10mb file? Are we talking about a few minutes or longer? I would think that missing a single fetchmail session would not create that large of a bottleneck... is there any reason that another 4-8 minutes of waiting causes an undue burden for your users?

Well - see I don't think it should take more than 3 to 4 mins at max for 10MB, but it depends on the ISPs network among other things. The point is that there could be many such large emails on a certain user account - lots of raw statistical data just waiting to be analysed, collected over months, maybe years sometimes....

Since there could be more than one large email in an account, and they could arrive quickly in succession at any time, there might be a problem I'm anticipating.

I haven't tested yet to see what happens - but in case I do get unacceptable delays - I'd like a backup plan..

Yours,
greyhammer

No ideas people? On multiple fetchmail sessions? I mean what if I wanted to run one session per user at the same time?

I know that an IMAP server can respond to more than one query at the same time. Isn't there some way to have multiple fetchmail sessions from the same machine at the same time to download email simultaneously from an IMAP server??