Callback Campaign Issue

[JinbeZame]

I tried to send callback invitation to invite my fc mates that has been inactive for over 90 days (93 days as of now - the account has been unsubscribed since 93 days ago too)
However, i have spent all 5 of my allowances and no email was received.

Are there any other pre requisites that he's not aware of?

[Serilda]

It just takes ages. The invites seem to go out on Tuesdays, but if you send the invite in-game on Sunday/Monday it will probably take over a week as it will miss the cut-off until then. The campaign sort of lacks any sense of immediate gratification which has made most of my attempts to get people to return fail right away :/

[LalaRu]

The account needs been inactive for at least 90 days, not the player. If you unsub, the account goes inactive at next billing cycle, not immediately, and it may happen days after you unsubbed.

It is possible their account still didn't reach the 90 days off, and mail not being sent for that reason.