Spam filters and the Spam folder

How it works, in short

Every incoming message is checked by the server's spam filter (Rspamd), which gives it a score: the higher it is, the more the message looks like spam. For each address, Enhance has three thresholds:

• “Spambox” — above this score, the message goes into the address's Spam folder, not the Inbox;
• “Greylist” — above this score, the message is delayed briefly: real email servers resend it after about 5 minutes and it is accepted on the second attempt, while many spam programs never come back;
• “Reject” — above this score, the message is refused. The sender usually gets a non-delivery message back from their provider.

On our addresses, the thresholds are usually 4 (Spambox), 6 (Greylist) and 8 (Reject): a slightly suspicious message goes to Spam, a very suspicious one is refused.

Before you start

• You need your Enhance login details (https://server.nbt-host.com). Spam settings are made by whoever has access to the hosting account, not from Webmail.
• We use the English names from the Enhance interface, exactly as they appear on screen. If the panel opens in another language, switch it to English from your account menu: “My account” » “Language”.

The steps

1. Open the address's spam settings

1. In Enhance, click “Emails” in the left menu.
2. Next to the address, open “Manage”.
3. In the page menu, choose “Spam settings”.

The settings are per address: if you want the same values on all of them, set them one by one.

2. Choose how strict it should be

1. Each threshold has a slider between “Strict” (on the left, low score: catches more) and “Permissive” (on the right, high score: lets more through).
2. Still getting a lot of spam in your Inbox? Move “Spambox” a step or two toward “Strict” — for example, from 4 to 3.
3. Good messages ending up in Spam? Move “Spambox” toward “Permissive” — for example, to 5 or 6.
4. A customer says their message was refused? Move “Reject” toward “Permissive” — for example, to 10 or 12. As long as the Reject threshold is higher than Spambox, suspicious messages go to Spam instead of being refused.
5. The change is saved automatically when you release the slider; the message “Spam settings updated” appears.

Keep the order Spambox < Greylist < Reject. Very low values (0–2) also send many good messages to Spam or refuse them.

3. Trusted senders and blocked senders

On the same page, under “Allow/block list”:

1. For a sender who should never end up in spam: in the “Allow” column, enter their address under “Email address” (for example contabilitate@firma-partener.ro) and click “Allow”. Messages from them get past all spam filters.
2. For a sender you don't want anything from: in the “Block” column, enter the address and click “Block”. Messages from them are refused — they don't even reach Spam.
3. The addresses you add appear in the “Allowed” and “Blocked” lists, respectively. You also remove them from there.

Good to know:

• The lists only accept full addresses. A whole domain (for example *@firma-partener.ro) cannot be added.
• The filter looks at the sender's technical address. For newsletters and messages sent through email platforms, it often differs from the address you see in “From”, so the list may not catch them.

4. The Spam folder

1. In Webmail: the Spam folder in the folder list (see Webmail: how to read your email in the browser).
2. On your phone and in Outlook (IMAP): the account's Spam folder; some apps show it as Junk.
3. Check it once a week. If you find a good message, move it to the Inbox and add the sender under “Allow”.
4. Messages in Spam also take up mailbox space. Empty the folder from Webmail, after you've looked through it.

5. Automatic sorting into folders

Rules such as “move all newsletters to folder X” don't exist in Enhance or in our Webmail. If you need them, you can create them in classic Outlook, with Rules — on an IMAP address, they only work while Outlook is open on your computer.

If something doesn't work

• Good messages end up in spam. Add the sender under “Allow” and, if it happens often, move “Spambox” toward “Permissive”. If the messages come from a partner, ask them to check their SPF, DKIM and DMARC (see Why my emails go to spam: SPF, DKIM, DMARC).
• You still get a lot of spam. Move “Spambox” toward “Strict” and block persistent senders. It also helps not to show your address as text on your website — bots harvest it from there; a contact form is safer.
• You get a lot of spam on addresses that don't exist. Check whether any address has “Catch-all” turned on (under “Manage”). The catch-all collects messages for any nonexistent address on the domain, so a lot of spam too; turn it off if you don't need it.
• A partner says their message was refused. The score went over “Reject”. Add them under “Allow” or raise the “Reject” threshold, then ask them to resend.
• Messages from a new sender are delayed by a few minutes. That's the “Greylist” effect: the message is accepted on the sender server's second attempt. If it bothers you, move “Greylist” toward “Permissive”.
• You don't see the Spam folder on your phone. The app hasn't shown all the folders yet. Open the account's folder list and refresh. In Webmail, under Settings » Folders, make sure the Spam folder is checked.
• The mailbox has filled up with spam. Empty the Spam folder from Webmail.