Hi Jakob,
I ran into this issue some weeks ago after updating to latest LTS Ubuntu
(Exim 4.90.1-1ubuntu1). Tracked this down to sa-exim which is screwing
up things as soon as more than one message is delivered over one
connection. By looking at the spool files I saw that random data was
missing/inserted.
On 26.07.2018 13:33, Jakobus Schürz via Exim-users wrote:
> Hi there!
>
> I get a lot of this errors:
>
> 4d 6.6K 1fhLuL-0003Kp-6q <systemd-devel-bounces@???>
> *** spool format error: size=7871 ***
> jakob@localhost
Similar, to what I saw in my system. Usually the random data was
inserted in the sa-exim header line which listed the hosts, where
scanning was performed.
> I use btrfs as filesystem. But scrubbing the filesystem ends without any
> error.
I initially thought of fs corruptions as well, but found no evidence.
> I have exim4 4.91-5 from debian/buster.
>
> Maybe it is a problem of exim? Or does it com from spamassassin?
It is most likely the sa-exim module. I did some tests and was not able
to get it to run reliably. Limiting exim to accept only one message per
connection was no option for my setup (too much traffic), it might be
for you.
I tried greylistd as alternative, however was not very satisfied (no
easy dependency on spamassassin scores, only time-based whitelisting,
stability issues, not very robust in regards of alternating IP adresses
most big providers use, esp. for IPv6). Finally just configured exim to
do spam checks via spamassassin and reject for scores >= 6.0. Works with
acceptable SPAM rejection (more or less no SPAM in mailboxes) and is
rock-solid stable.
hth,
Thomas
