FortiMail Licensing when just using rewrite function

[DenBal]

Hi,

We have a customer that needs recipient rewriting and I proposed to use a VM02 cloud Gateway. The purpose is to rewrite all old email addresses for 2 year to a new email address (they're splitting O365 tenants) until they are no longer used. We will not be using any feature, except the rewriting of 800 email addresses.

How do we license this? Is it enough to have just a few licenses as the users will not be logging in to release email or anything or do we have to get a license for every email address?

Any better proposals?

[AEK]

Hello

Do you mean you want use FortiMail only for sender rewriting and not for mail security?

[DenBal]

Correct, not for mail security. Just rewriting recipient.

Company aaa.com is splitting into bbb.com, ccc.com, ddd.com and eee.com but they still want to receive mail on a.user@aaa.com which is rewritten to for example a.user@bbb.com. Needs to be rewritten because a domain can only be verified in 1 O365 tenant, preferably with a cloud solution on a per-year subscription.

[AEK]

I don't  think is a good idea to acquire a whole FortiMail just for this feature. I think this is doable at O365 level. I've already seen a local company did something similar only with Exchange on-premises.

[DenBal]

With Exchange On-prem it's possible, granted. Exchange Online not so much, you can only rewrite the sender, not the recipient.

As there is no more on-prem environment, we abandoned the Exchange on-prem route.

[AEK]

As per my knowledge the local company didn't really do a rewrite in the strict sense, but like a domain alias or something like that. I wonder if this is possible in O365.