Well, it turned out to be a combination of two things: - AUXLIBS is missing -lsqlite3 and -lpthread - sqlite is not added to /etc/postfix/dynamicmaps.cf
The first time I added the missing flags to AUXLIBS it didn't make a difference because sqlite wasn't even listed in dynamicmaps.cf. After adding it, I got: fatal: load_library_symbols: dlopen failure loading /usr/lib/postfix/dict_sqlite.so: /usr/lib/postfix/dict_sqlite.so: undefined symbol: sqlite3_open And then adding the flags fixed that. I examined postfix.postinst but I'm not familiar with the process and I wasn't sure where to add the required addmap. I see two places were tcp and other maps are added to dynamicmaps.cf but I didn't understand very well the relationship between that code there and the postfix-{msql,pgsql,...} packages. How come postfix.postinst calls addmap msyql and it doesn't add it to dynamicmaps.cf after install? Anyway, I hope this information is helpful in fixing the package.