All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
There is no harm religiously in inviting people to attend marriage in the mosque, whether this is on a rare occasion or a constant habit. The evidence about this is that our Hanafi, Shaafi'ee and Hanbali, schools and some scholars of the Maaliki school stated that it is desirable to conduct marriage contracts in mosques, so this is evidence that it is permissible to invite people to the marriage in the mosque.
Allaah Knows best.