*sigh*
gld has packed in for the last time on me. Since I now use the university system to read my work email, I failed to notice that my personal mail had quietly stopped working.
Well, quietly from my side. From the public side, it was returning internal configuration errors left right and centre.
It was only when my brother noticed he had missed some emails that I looked and found that gld had fallen over again. You would think that postfix would handle this sort of failure gracefully – more spam being preferable to no email at all – but no.
So now I am going to try policyd instead, to see if it is any more stable.
I did install policyd in the end (debian package postfix-policyd) and it has been behaving well so far using the out-of-box configuration.
Touch wood.