The MailSure blog
Email verification, deliverability and clean lists
Practical guides for marketers and developers who want their email to reach real people.
Developers2 min read
Why a regex is not enough for email validation
A regular expression can check the shape of an address, and that is all. Here is what it misses, and what to do instead.
Developers2 min read
Verifying Gmail, Outlook and other big mailbox providers
Gmail and Hotmail/Outlook tell a verifier whether a mailbox exists. Company domains on Microsoft 365 and Google Workspace vary, and Yahoo and iCloud are cautious. Here is how each behaves.
Developers2 min read
How SMTP mailbox verification works (and its limits)
A verifier can ask a mail server whether a mailbox exists without sending an email. Here is the conversation, and why it isn't always conclusive.
Developers2 min read
How to add email validation to your signup form
A practical walkthrough of calling the Mailsure API from your server, handling each result and keeping the form friendly.