Sendmaster

by lewis@conditionalaccess.uk · Developer Tools

Manifest V3 Free

View in Chrome Web Store Data as of 16 Oct 2026

Check your domain's outbound mail authentication (SPF, DKIM, DMARC) with inline validation and a copy-friendly summary.

Users

+1 in 30 days

Rating

0.0 / 5

unchanged in 30 days

Ratings

0 in 30 days

Store rank

#195K

#163K among extensions

Version

0.2.0

updated 24 Jun 2026

Users

monthly, 5 months

Latest, 16 Oct 2026: 10 usersMove the mouse over the chart for any month

Ratings count

monthly, 5 months

Latest, 16 Oct 2026: 0 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About Sendmaster

Sendmaster is a browser extension that displays SPF, DKIM, and DMARC DNS records for the website you are currently viewing to help you verify your configuration or help to spot potential issues. Misconfiguration of DNS records can lead to impersonation of your domain or your legitimate outbound email landing in junk folders by default. What the extension does: When you click the toolbar icon on a tab, the extension reads the hostname of that tab, derives the root domain, and queries DNS TXT and NS records for it. The results render inside the popup.