I can certainly sympathize with this. Over the past 20 years I've gotten bit several times by 3rd party email services shutting down with little or no notice and even had access to my email services sold to spammers by the providers I was paying for it.
The last time it happened I'd created a "Mandrill" account while developing an app and just a few weeks before releasing it I got a notice saying "Mandrill has been acquired by MailChimp" and I would need to create a new account with MailChimp.
That was last straw for me using 3rd Party email services. I spent the next several weeks setting up a "MAIB" (Mail-in-a-Box) server on a DigitalOcean VPS.
Setting up that server on DigitalOcean had it's own hurdles I didn't see coming, one of which was my MAIB server IP was black listed before I even sent an email because it was running on the DO platform. I contacted DOs support and all they could offer was "We recommend you don't use DO for email servers". Apparently spammers find it appealing to do this too so some email services, like AOL, Hotmail, etc block everything coming from DO and require you request to be whitelisted.
Because of that it ended up taking a few more months to reveal and deal with all the issues that popped up and that was painful too. It ended up being worth the effort though.
It's been working great for over 2 years now and there are some additional benefits I'd not expected when I first started working on it. One of the biggest is MAIB has a built-in DNS server too. I didn't use it at first but after playing with it a bit I ended up moving all my sites over to it and configuring my desktop Mac to use it first.
Given the chance the only thing I'd do different is to set up my own email server before I ran into this kind of "Mailchimp" problem again (because my experience is it will) so I could work through those issues first and transition to it from a 3rd party service at my leisure.
It's not an easy slog, but MAIB made it a hellava lot easier.
https://mailinabox.email
The last time it happened I'd created a "Mandrill" account while developing an app and just a few weeks before releasing it I got a notice saying "Mandrill has been acquired by MailChimp" and I would need to create a new account with MailChimp.
That was last straw for me using 3rd Party email services. I spent the next several weeks setting up a "MAIB" (Mail-in-a-Box) server on a DigitalOcean VPS.
Setting up that server on DigitalOcean had it's own hurdles I didn't see coming, one of which was my MAIB server IP was black listed before I even sent an email because it was running on the DO platform. I contacted DOs support and all they could offer was "We recommend you don't use DO for email servers". Apparently spammers find it appealing to do this too so some email services, like AOL, Hotmail, etc block everything coming from DO and require you request to be whitelisted.
Because of that it ended up taking a few more months to reveal and deal with all the issues that popped up and that was painful too. It ended up being worth the effort though.
It's been working great for over 2 years now and there are some additional benefits I'd not expected when I first started working on it. One of the biggest is MAIB has a built-in DNS server too. I didn't use it at first but after playing with it a bit I ended up moving all my sites over to it and configuring my desktop Mac to use it first.
Given the chance the only thing I'd do different is to set up my own email server before I ran into this kind of "Mailchimp" problem again (because my experience is it will) so I could work through those issues first and transition to it from a 3rd party service at my leisure.
It's not an easy slog, but MAIB made it a hellava lot easier.
https://mailinabox.email