Forwarding into Gmail became unreliable

Question

Problem

I was using the following method since years, and never had any problems with it:

1. Setting up a forwarder at a third party host (can also be cheap shared hosting) to my personal Gmail account (not Google Apps)
2. Using Gmail to check the emails
3. Using Gmail to write and send emails, also utilizing the "send as" feature

However, since last week I (and at least two other people I know, on different domains) encounter unreliabilities with this method. Some emails do not come through (and also do not bounce back), while others do. That obviously makes it hard to recognize.

Those lost mails do not appear anywhere in Gmail, not the spam folder, and not the all emails folder. They also do not appear in the search.

I suspect some spam filtering mechanism to have changed. Google's best practices mention the possibility of messages getting blocked before entering gmail, however I do have set up a "send as" address, which, according to that article, prevents those mechanisms from acting.

So:

1. Watch out if you are using the same method of forwarding into Gmail.
2. Any ideas how to prevent this from happening? Or any suggested workarounds?

My current emergency workaround

1. I set up a real inbox in my third party host, called [email protected].
2. I created a similar forwarder like my normal one, to also forward to this pop inbox
3. I check the pop inbox via Gmail. And voilà, some emails only make it into my inbox via this way.

Unfortunately it's a bit of a pain to set up. Switching to pop inboxes would reduce the necessary steps, but it also some work (I got a lot of addresses) and comes with other disadvantages (e.g. speed).

Answer 1

HostGator now explains what's happening when setting up a forwarder to a Gmail address:

Why Should I Use Fetch Mail Instead of an Email Forwarder?

Unfortunately, it is very common for forwarding to cause blacklisting with many large email providers. This most commonly occurs when large amounts of mail are forwarded and then marked as spam after it has been received in the end user's inbox. This results in your server's sending reputation being penalized since it was the last server to send the mail. Ultimately, your server will become blacklisted with the email provider and it will affect all of the users on the server.

A solution to this is to stop the forward altogether. Using a mail fetcher, you can access mail in a remote system without having the mail routed through that system's server. This way, you can mark the message as spam without it affecting your email server's reputation.

Source: https://support.hostgator.com/articles/specialized-help/email/google-mail-fetcher#fetch