Hi, we are planning following scenario:
What we have now:
Domain test.de associated to a Webserver product at our hosting provider.
The MX entry for test.de goes to the mail cluster of the hosting provider.
We have mailboxes firstname.lastname@example.org online hosted form the hosting provider.
We have an internal exchange server that fetches e-mail from online malboxes via POP3.
Outgoing mail from exchange to the internet is sent by using the smarthost (SMTP) from out hosting provider.
Newsletter-tools are also using the provider`s smarthost for sending e-mails withe the sender adresse e.g. email@example.com.
What we are planning:
Migrate our internal mailboxes over to Office 365.
Change the MX record for test.de to Office 365.
We will have a spf entry entry that includes as well the Office365 server and the mailcluster servers from the hosting provider.
The domain managemet for test.de stays at the hosting provider.
Is it possible and save that we will still use the mailboxe firstname.lastname@example.org that is located at the hosting provider for outgoing smtp mail (as smarthost) with newsletter tools?
The background is that Office 365 limits outgoing mail per minute and day and that ist notacceptable for newsletters.
I`m afraid that there could be problems with spam-handling if we send as sender email@example.com and the MX record shows to another server (Office 365) than the sending server (hosting provider). Would there be a problem with "Smtp Reverse Dns Mismatch"?
How do you handle that?
Many thanks in advance!