I want to change clamav from update.script to the one mentioned in options.conf of custombuild.

Now I used this guide from Sellerone, to remove the update.script installation:
(However in the first "find" line the last / must not be there).

I also disabled the changes I made in exim.conf mentioned in the first post of update.script.

After that, I installed clamav using the guide of Sellerone which is the same here:

So far so good.

Now in some posts I see users have this line in their exim.conf:

av_scanner = clamd:/var/run/clamav/clamd
The /var/run/clamav directory is present again in my system after building with custombuild.
However, the directory is empty.

And the DA help does not tell me to put this line in exim.conf, but use this one:
av_scanner = clamd: 3310
Which line is best, and if /var/run/clamav/clamd is not used anymore, why is the /var/run/clamav still made by Custombuild?"

Next to that I got this warning when clamd was restarted during installation:
LibClamAV Warning: *** The virus database is older than 7 days! ***
LibClamAV Warning: *** Please update it as soon as possible. ***
How do I update the database now I used the custombuild instllation? And is there a way to do this automatically?