topic Re: Spam filtering threshold in Email

Spam filtering threshold

glocal — Sun, 27 Sep 2026 13:12:00 GMT

Greenby's spam filtering is much more aggressive here even though my setup is exactly the same as it was with Plusnet. My spam threshold is set to 3 and it worked well for years. In the headers I see that what makes incoming email look more suspicious is that it is usually sent to name@mydomain.com and my domain host forwards it to name@account.plus.com. That alone adds 2 to the spam score before scoring even starts. Is there a way to tell the spam filter that this forwarding is actually OK?

I know I can increase the threshold on Greenby's website, but that would relax filtering of actual spam.

Re: Spam filtering threshold

PhilipHeyes — Sun, 27 Sep 2026 13:20:00 GMT

In the previous tab of the Greenby portal is Filters

Try adding the email address <name@mydomain.com> as a Whitelist entry.

Re: Spam filtering threshold

MisterW — Sun, 27 Sep 2026 13:25:09 GMT

@glocal

I see that what makes incoming email look more suspicious is that it is usually sent to name@mydomain.com and my domain host forwards it to name@account.plus.com. That alone adds 2 to the spam score before scoring even starts.

Does your domain forwarder support SRS (Sender Rewrite System) ?

If it does, then forwarded mail shouldn't have an increased spam level. If it doesn't then then SPF will fail and you have a good possibility of mail being rejected let alone an increased spam score.

Re: Spam filtering threshold

glocal — Mon, 28 Sep 2026 11:21:17 GMT

@PhilipHeyes wrote:

In the previous tab of the Greenby portal is Filters

Try adding the email address <name@mydomain.com> as a Whitelist entry.

I believe that's for senders of incoming email. There is no harm in adding my addresses there, so I have and it makes no difference. Most of my incoming email goes to the spam folder with my spam threshold set to 3. Usually there is a header like this:

X-Spam-Flag: YES

But some messages even have conflicting headers:

X-Spam-Flag: NO
...
X-Spamd-Result: default: False [4.69 / 3.00];
FORGED_RECIPIENTS(2.00)[m:my_email_address1,s:my_email_address2];
...
X-Spam: Yes

I think I will switch spam filtering off to see what happens. So far, it only catches legit email anyway.

Re: Spam filtering threshold

glocal — Mon, 28 Sep 2026 11:25:37 GMT

@MisterW wrote:

Does your domain forwarder support SRS (Sender Rewrite System) ?

If it does, then forwarded mail shouldn't have an increased spam level. If it doesn't then then SPF will fail and you have a good possibility of mail being rejected let alone an increased spam score.

Ionos claim they do support SRS (that's 'Sender Rewriting Scheme' I think). And all worked fine for over a decade while Plusnet handled my email. I hardly got any rejections. It all changed the day I was switched to Greenby.