Damn, that's it!! Thank You for finding out about this.
By the way, with me the file already existed and I just added the line to it.
Now strangely it looks like this, maybe because I altered settings in
enigmail:
# GPGConf disabled this option here at Tu 20 Okt 2015 14:43:58 CEST
# default-cache-ttl 300
# GPGConf disabled this option here at Tu 20 Okt 2015 14:43:58 CEST
# max-cache-ttl 999999
use-standard-socket
###+++--- GPGConf ---+++###
default-cache-ttl 3600
max-cache-ttl 36000
###+++--- GPGConf ---+++### Tu 20 Okt 2015 14:43:58 CEST
# GPGConf edited this configuration file.
# It will disable options before this marked block, but it will
# never change anything below these lines.
