Email Headers last modified 2022-04-18

The purpose of this page is to describe how to access and analyze email headers in order to make effective rules to either block or allow senders.

All email server administrations use some form of spam-detection software to screen email for spam and quarantine suspected spam into Spam folders. The OlympusNet Spam folder can be seen using Webmail (and devices set up using IMAP).

Log in to Webmail with your olympus.net email address and password.

To get desired emails to the Inbox in the future after recovering email that has been diverted to the Spam folder, an Allow Sender entry must be made in the spam settings. Likewise, emails you consider spam can be blocked in the spam settings.

To make effective entries to the Block or Allow list, the email headers must be looked at. The automatic tools in Webmail to Block Sender or Allow Sender do not work effectively.

To view email headers in Webmail:

1. Select the email you want to allow or block.
2. Below the subject line and From field of the open email, select Details.
   
   
   
3. Then select All headers.
   

The results are a full page of technical language that charts an email’s progress through a number of server handoffs before it reaches the email server that delivers to you.

In the screenshot below, the first several lines of a page of headers is shown. Looking at both the From field (bottom of screenshot) and Return-Path (top of screenshot), the email address is the same: xxx@product.libtestchamber.com

If the From and Return-Path do not match, it is best to make two entries to the block or allow list using the domain from both fields.
Note that both the From and Return-Path may be forged by a spammer.

If you want (or don’t want) any emails from the domain, no matter who the individual sender is in the domain, your entry is best made using *@*libtestchamber.com. A domain is the last two terms following an @ sign. In this example, libtestchamber.com is the domain.

The wildcards, represented as asterisks, say block any sender from the domain for the first asterisk. The asterisk following the @ character covers the word product. Domains may often add various other words besides product as shown in this example, and the second asterisk would include any other term entered before the root domain, libtestchamber.com. *@*libtestchamber.com is added to the Block list.

Single, ordinary emails from individuals can also be added to the lists, as desired. It is always a good idea to check the headers, as known friends aren’t necessarily using the email address visible on the surface of an email.

Viewing email headers using a desktop email application is similar. The screenshots below show viewing headers using Apple Mail. Select an email, then select View in the toolbar, and hover over Message. Select All Headers to the right.

The Headers differ somewhat between various email programs/applications and Webmail. Return Path is marked in red shown below, as it was collected from the headers in the Webmail example above.

See how to add the entry using the Blocked and Allowed Senders in Webmail.