> I would like to know if there is any way to implement cache for the
> smtpd_recipient_restrictions parameter?
> I use MySql to store a table full of non-existent users, which I was
> saving from email accounts that have been compromised by viruses on
> the PC.
> Any recommendation?
It's not clear exactly what you're asking for...
Please clearly explain the problem you're trying to solve for more