You misunderstand jjeaff. He suggests making the MX of yourdomain.tld point to Gmail's MTAs. This is what he means by "forwarding email". This is the best-practice way to do it and works perfectly well.
Re:I Can No Longer Recommend Google Fi
by toomuchtodo on Friday January 11, 2019 @11:31PM
(#18889665)
This is inaccurate.
I have namecheap forward all of my email from *@my-domain-name.com to [email protected]. Works no problem, has for several years. Prepared for the eventual switch to FastMail when they support multi-label messages.
The only messages that end up in my spam folder are spam for knock off online pharmacies.
Hmm [goes off and does more research].
Okay, it appears this is so common that gmail has some guidelines that if people follow they are are usually okay:
https://support.google.com/mail/answer/175365?hl=en
It does look like namecheap filters spam aggressively so possibly that helps.
In general be careful for the reasons I mention. But it looks like if you follow the guidelines with gmail then you'll be good.
Sorry for the inaccurate information.
The problem is that from gmail's point of view your registrar is now sending it a lot of spam. So it'll block the registrar or filter it more aggressively.
Also if you get email from a 3rd party who uses domain-keys, spf, etc (eg just about everyone) then those emails will be failing all the checks when gmail receives them.