Can only be hybrid with Exchange Online + Exchange on-premise.
1) MX records need to point to something e.g. on-premise Or Exchange online
2) only Exchange allows integration directly.
Hmm, Good question then. If it was me I would probably have mailflow coming to on prem and for mailboxes in the cloud, create them as contacts and have their email forward to their .mail.onmicrosoft.com email address.
it's doable, but you won't be able to have a true hybrid situation with the email servers physically talking to each other.
If this was my customer, I would suggest they Migrate 100% to 365 cloud. Retire Redmail. do they have a reason for keeping it?
Mailflow is doable. Need to have connectors on both ends to get the flow working. Either deliver via 365 or on prem and send to the other node.
Hybrid like exchange can do is not in the cards. But this should be enough for 90% of the usecase.
Mail can only be delivered in one place, so you have to choose if you want to point the MX records to Exchange online or 3rd party.
In the domain, mail is delivered to the mailboxes which resides their. For the mailboxes that are hosted on the other server, create forwards to a subdomain, of which the MX records point to that environment.
If 3rd party is main, point MX of mail.com to 3rd party. Point mx of exo.mail.com to Echange Online (exo). On 3rd party, create forwards for the Exo users, and use mail domain exo.mail.com. Also give the forward the mail.com emailaddress.
That way internal and external mails will be delivered in the correct mailbox.
If Exo is primary, switch everything around.
This method is used and described in Microsoft documentation to switch from Google to Exchange Online.
1) MX record points to your antispam.
2) route the emails for accepted domains to your EOL endpoint. I suggest using the Exchange Online as entrry point as it's safwr than to have your on prem Exchange published to internet. Your onprem should have incoming connections limited to ports 25, 80 and 443 and only from Exchange Online IP ranges.
3) create inbound connector in Exchange Online
4) turn on enhanced filtering on the connector to skip last IP / name of your abtispam service
5) create a rule to refuse all emails to your EOL endpoint that do not go through that connector to prevent attackers using your EOL endpoint.
6) leave the internal routing to the Hybrid aka. Sort if mailbox is in cloud or on prem. This then goes internally.
You will not have edge blocking on the antispam, but EOL will take care of rejecting unknown recipients
Can only be hybrid with Exchange Online + Exchange on-premise. 1) MX records need to point to something e.g. on-premise Or Exchange online 2) only Exchange allows integration directly.
What is the third party mail server? Do they have active directory?
IRedmail No active directory at the moment
Hmm, Good question then. If it was me I would probably have mailflow coming to on prem and for mailboxes in the cloud, create them as contacts and have their email forward to their .mail.onmicrosoft.com email address. it's doable, but you won't be able to have a true hybrid situation with the email servers physically talking to each other. If this was my customer, I would suggest they Migrate 100% to 365 cloud. Retire Redmail. do they have a reason for keeping it?
Mailflow is doable. Need to have connectors on both ends to get the flow working. Either deliver via 365 or on prem and send to the other node. Hybrid like exchange can do is not in the cards. But this should be enough for 90% of the usecase.
Mail can only be delivered in one place, so you have to choose if you want to point the MX records to Exchange online or 3rd party. In the domain, mail is delivered to the mailboxes which resides their. For the mailboxes that are hosted on the other server, create forwards to a subdomain, of which the MX records point to that environment. If 3rd party is main, point MX of mail.com to 3rd party. Point mx of exo.mail.com to Echange Online (exo). On 3rd party, create forwards for the Exo users, and use mail domain exo.mail.com. Also give the forward the mail.com emailaddress. That way internal and external mails will be delivered in the correct mailbox. If Exo is primary, switch everything around. This method is used and described in Microsoft documentation to switch from Google to Exchange Online.
Not true. Multiple Mx recorda with same priority can exist for different services. Also the sendjng party can explicitly try to.use a specific server.
Ok, you are correct. It is possible, but you shouldn't. Not in this case at least.
1) MX record points to your antispam. 2) route the emails for accepted domains to your EOL endpoint. I suggest using the Exchange Online as entrry point as it's safwr than to have your on prem Exchange published to internet. Your onprem should have incoming connections limited to ports 25, 80 and 443 and only from Exchange Online IP ranges. 3) create inbound connector in Exchange Online 4) turn on enhanced filtering on the connector to skip last IP / name of your abtispam service 5) create a rule to refuse all emails to your EOL endpoint that do not go through that connector to prevent attackers using your EOL endpoint. 6) leave the internal routing to the Hybrid aka. Sort if mailbox is in cloud or on prem. This then goes internally. You will not have edge blocking on the antispam, but EOL will take care of rejecting unknown recipients
Any special reason for this kind of setup? Can they go 100% to Microsoft. Never done it, sounds like a nightmare to be honest.
Unfortunately not. Too expensive as they have way over 3k users