cross-email-validator

UPDATE: 4/2021 THIS REPO IS NO LONGER USED UPDATE: 3/2020 This is only being used in BeeWell's older mobile app, once that is replace by GetMyCarePlan this can be removed.

Goes beyond validating the characters that make up the email, and additionally performs DNS and mailbox checks to ensure that the email address is valid. Does all the network calls using cross-fetch, so it works in the browser, on React Native, on Node, and anywhere else you want to run it.

Synposis

Install

yarn add cross-email-validator

Execute

import validateEmail from "cross-email-validator"

await validateEmail("developer+rnev@beewell.health"); // returns true
await validateEmail("@beewell.health"); // returns false
await validateEmail("developer+rnev@health"); // returns false

Validation Phases

Step 1: Syntax

These are performed sequentially.

• It first ensures that the value is a non-empty string, that the character '@' is in the address precisely once, and that '@' is not the first or last character.
• It then checks that the TLD is in the TLD list given by tlds.
• Then uses validator/lib/isEmail for validating the e-mail address format. This does an extensive amount of checks, with a whole suite of checks specifically for @gmail.com addresses.

Step 2: Network Checks

These are performed concurrenctly.

• Calls out to the 1.1.1.1 DNS over HTTPS server to ensure that there exists at least one MX record for the domain.
• At the same time, calls out to the Kickbox "disposable email" API to validate that the e-mail domain is not a disposable email domain.
• It'd be nice to do an SMTP check, but it's unclear how to do that from within React Native without unlinking.

Note that any network check that errors out will be counted as a pass. So if there is no internet, the internet connection is slow, or the server is down, then it is equivalent to the network check returning valid.

Browser-Friendly Version of the File

If you're looking for a Flow-free, minified version of the script (say, to include in a webpage), then look no further than ./dist/browser/index.js. It is produced using Parcel and automatically updated before every commit. The browser support is specified in ./.browserslist.rc -- for more information, see browserslist on GitHub.

When you load that file, the global variable CrossEmail will be provided which links to this module.

Node-Friendly Version of the File

Currently, the ./index.js file is Node-friendly, but that may not always remain the case. We have the folders ./dist/browser/ and ./dist/node/ for the distinct builds. For the moment, ./dist/node/index.js currently just symlinks back to ./index.js, but don't depend on that.

License

MIT. See the file named LICENSE in this directory for details.

Inspiration

email-deep-validator