How it works Gmail and Zoho Mail · free to read
Everything about email opens.
Practical guides on knowing whether your emails get read, in Gmail and in Zoho Mail. Written by the people building mailcheck.
How it works 
Privacy Is an Email Tracking Chrome Extension Safe? Permissions Explained
Before installing an email tracking Chrome extension, check what it can access. The permissions to look for, the red flags, and exactly what mailcheck asks for.
Comparison Best Email Tracker Chrome Extensions in 2026, Compared
Mailtrack, Streak, HubSpot Sales, Saleshandy and mailcheck: what each email tracker Chrome extension does best, which inboxes it supports, and who it is for.
Gmail A Simple Follow-Up System in Gmail
Labels, snooze and open tracking: a follow-up system that lives entirely in Gmail, takes ten minutes a day, and never lets a proposal slip.
Use cases Email Tracking for Nonprofits and Fundraising
Grant applications, sponsor proposals, major donor emails: a nonprofit's most important emails are one-to-one. How open tracking helps follow up at the right time.
Deliverability Why Your Emails Land in Gmail's Promotions Tab
A one-to-one email in the Promotions tab is rarely read in time. What pushes it there, and what keeps business emails in the Primary inbox.
Product 5 Questions to Ask Claude About Your Email Opens
With the mailcheck connector, Claude or any AI agent can answer questions about your tracked emails. Five questions worth asking every week.
Productivity How to Write Subject Lines That Get One-to-One Emails Opened
Marketing subject line advice does not fit a proposal sent to one person. What works for one-to-one business email, with examples you can measure.
Privacy