I own my own domain name and use it's email service. Any reason to still go to a third party email provider?
As far as a messenger, what's wrong with SMS, over?
Unfortunately, there no way for me to tell you how secure your email service is. There are two ways in which email can be secured. They email itself can have end to end encryption, in which case, the message cannot be read while enroute. The other way is for it to have a digital signature. That doesn't make it unreadable, but it ensures the email is not modified enroute. You would have to ask you email service provider what they have for options.
When you refer to SMS, that's really more of a messaging format than anything (plain text). If you were thinking "text messages" over your cellular carrier service, well, that's not very secure actually. When I was referring to messengers, I am talking about a standalone app that can do instant messaging. Seems similar but the backbone is different. It seems similar simply because most cellular text messages have multimedia capability today so the lines have become grey.
An instant messenger is going to go across the Internet as opposed to the phone providers data network. The goal would be to have a messenger that provides end to end encryption and NO LOGGING of your data. That's why I suggested Signal in my post. Still researching that one.
