So recently I had a client that wanted any email sent to any domain to arrive in all email systems, why? can’t tell you that but it is possible and here’s 2 solutions how.
- Build your own email filter based on postfix, do all your anti-spam, anti-spoofing and email routing there, here’s a great post on how that works from PJR
- Use Google Apps’ Dual Delivery System.
So Google Apps, those geniuses of email and all things cloud (ad supported cloud, if you didn’t realize that), have created a way to do Dual Delivery, with nearly any manipulation of email possible, including a way to ensure office365 whitelists the emails coming from google apps as you’ve just broken every SPF/DKIM/DMARC record in existence. What you end up doing is routing a copy of the email to a new email address, but spoofing the from address as the original sender. This way you receive your email on your Office365, Google Apps, Hotmail, personal email, any email, and some old groupwise email system you still have on premise, it doesn’t matter. What does matter is some level of consistency. As long as all email addresses have the same alias, you can re-route them, personally I’m a fan of first.last or flast, but as long as it’s the same, it will work.
Downsides? Well if google apps has some issue, that’s going to affect all your email domains and there may be a bug send sending to o365 users from o365 or google apps from google apps.
Questions Comments Below and of course if you’re looking for help on this project or any email projects use the contact form!