[Evolution-users] Constantly have to clear cache

[Pete Biggs]

On Sun, 2025-11-09 at 11:38 -0500, Steve Phillips wrote:
> Well, I'm not sure if that setting suggestion was for debugging
> purposes but the issue has not occurred since I set it to single
> connections.

You can leave it as it is - I have had it set like that on multiple
accounts for many years. It may even be correct to set it to '1'.

> 
> Does that mean my race condition theory was correct?
> 
The setting controls how many connections are made to the server - the
theory being that with more connections you can download multiple
messages at a time, so things feel faster. However its efficacy is
largely dependent on the server and some servers really don't like it -
or at least the admins configure the software to only allow a single
connection at a time from clients. (From an admin point of view if
everyone use 3 or 4 connections, that represents a large increase in
load on a busy server.)

So it's not a race condition per se, although it does feel like it.
What I think happens is that when the server sees a second connection
start up it terminates the current connection, and if that is in the
process of downloading the message body, Evolution will "see" an empty
cache file and complain. (I don't actually know the internal workings
of Evolution that well, but it seems to be an explanation!) 

In modern high speed networks I don't think the multiple connections
are that important. A side effect is that if you are downloading a
large message, then the connection will block for a while. But
personally I think it's a fairly minor inconvenience to get a much more
stable experience.

P.