Keep your mail out of spam

Gmail, Outlook.com and other large providers decide in a fraction of a second whether your message goes to the inbox or to spam. They look at three things: can the sender be verified, what is this domain's reputation, and does the message look like spam. FiniteHost takes care of the server side (encrypted sending, DKIM signing, a dedicated mail server). This guide covers the parts only you can control, and how to test them.

Before you start#

• The four mail DNS records should be in place (Email DNS records).
• Have a personal Gmail or Outlook.com address to send tests to.

Step 1: Test your domain#

Gmail "Show original"#

1. Send a normal message (a few sentences, no attachment) from your FiniteHost mailbox to your Gmail address.
2. Open it in Gmail on a computer. Click the three-dot menu (⋮) next to Reply → Show original.
3. The summary at the top should show:

If any line says FAIL, SOFTFAIL or NONE, fix that record first; nothing else matters as much.

Outlook.com#

Open the message → three-dot menu → View → View message source. Search the text for Authentication-Results. Look for spf=pass, dkim=pass and dmarc=pass.

Online checkers#

• mail-tester.com gives you a one-time address. Send a typical message to it and you get a score out of 10 with explanations.
• Google Admin Toolbox Messageheader (toolbox.googleapps.com/apps/messageheader) and MXToolbox Email Header Analyzer read a full header that you paste in and show each hop and check.

Copy the full header from "Show original" (Gmail) or "View message source" (Outlook.com).

Step 2: Read the key header lines#

A message header is a list of Name: value lines. The ones that matter here:

Authentication-Results: mx.google.com;
       dkim=pass header.i=@acme.in header.s=fh1;
       spf=pass smtp.mailfrom=priya@acme.in;
       dmarc=pass (p=QUARANTINE) header.from=acme.in
DKIM-Signature: v=1; a=rsa-sha256; d=acme.in; s=fh1; ...
Received: from mx1.finitehost.com (mx1.finitehost.com [108.181.215.252]) ...

• header.s=fh1 and d=acme.in: the message was signed with your domain's FiniteHost DKIM key.
• smtp.mailfrom=…@acme.in with spf=pass: the FiniteHost server is allowed to send for your domain.
• dmarc=pass: SPF or DKIM passed for the same domain that is in the From line.

Step 3: Why mail still goes to spam, and the fixes#

Work down this list. The first items have the biggest effect.

1. A DNS record is missing or wrong. Re-check with Email DNS records. Two SPF records, a truncated DKIM key and an old MX record are the usual culprits.
2. The domain is brand new or has never sent mail. Providers are cautious with unknown domains. Start with normal one-to-one conversations; reputation builds over the first weeks as people reply and do not mark you as spam.
3. Recipients marked your mail as spam. Every "Report spam" click lowers your reputation with that provider. Send only to people who expect your mail, and make it easy to say no.
4. Bulk sending from a personal mailbox. Newsletters to hundreds of people from priya@acme.in look like spam and hit the sending limits (Limits and policies). Use a dedicated newsletter service for marketing, set up for your domain, and keep FiniteHost mailboxes for conversations.
5. Content that looks like spam. Avoid: a message that is only an image or only a link; link shorteners; ALL CAPS subjects and many exclamation marks; attachments such as .zip or .exe; a mismatch between the link text and where the link goes.
6. The From name does not match the address. Acme Accounts <priya@acme.in> is fine; a display name containing another domain's address looks like impersonation.
7. Sending from another service with your address. If a website, CRM or invoicing tool sends as @acme.in through its own servers, it fails SPF and DKIM for your domain and DMARC tells receivers to quarantine it. Set that service up with its own SPF include and DKIM for your domain, or let it send through your FiniteHost mailbox with SMTP authentication (Send email from your website or app).

Incoming spam: what FiniteHost filters#

Every message that arrives is scored by a spam filter before it reaches your mailbox:

• Very high scores are refused outright. The sender's server gets an error; you never see the message.
• Suspicious scores are delivered with spam headers (X-Spam-Level, X-Spamd-Bar) that mail apps can filter on.
• Messages from unknown servers that look slightly suspicious may be greylisted: the first delivery attempt is asked to retry later. Real mail servers retry automatically, so the message arrives a few minutes late. Spam robots usually never retry.

Webmail also shows trust chips next to the sender (see Security and privacy in webmail): Verified when the sender passed SPF/DKIM/DMARC, Failed auth when a check failed, Caution when the display name or reply-to looks like impersonation, and External sender for mail from outside your domain.

Spam that gets through#

• In webmail, select the message and click Junk on the ribbon (or Mark as spam in the right-click menu). It moves to the Spam folder.
• To clear many messages from one sender at once, right-click a message → Sweep from sender… → Move all to Trash.
• To handle future messages automatically, create a rule: Rules and filters.

Troubleshooting#

What's next#

• Limits and policies
• Email troubleshooting
• Rules and filters in webmail