Merge pull request #1555 from anirudh-chhangani/main

Add mailcrab.

README.md

@@ -1205,6 +1205,7 @@ See also [About Rust’s Machine Learning Community](https://medium.com/@autumn_
 * [stalwartlabs/mail-auth](https://github.com/stalwartlabs/mail-auth) [[mail-auth](https://crates.io/crates/mail-auth)] - DKIM, ARC, SPF and DMARC message authentication library [![build badge](https://github.com/stalwartlabs/mail-auth/actions/workflows/rust.yml/badge.svg)](https://github.com/stalwartlabs/mail-auth/actions/workflows/rust.yml)
 * [stalwartlabs/mail-parser](https://github.com/stalwartlabs/mail-parser) [[mail-parser](https://crates.io/crates/mail-parser)] - A fast and robust e-mail parsing library with full MIME support [![build badge](https://github.com/stalwartlabs/mail-parser/actions/workflows/rust.yml/badge.svg)](https://github.com/stalwartlabs/mail-parser/actions/workflows/rust.yml)
 * [stalwartlabs/mail-send](https://github.com/stalwartlabs/mail-send) [[mail-send](https://crates.io/crates/mail-send)] - E-mail builder and SMTP client library with DKIM support [![build badge](https://github.com/stalwartlabs/mail-send/actions/workflows/rust.yml/badge.svg)](https://github.com/stalwartlabs/mail-send/actions/workflows/rust.yml)
+* [tweedegolf/mailcrab](https://github.com/tweedegolf/mailcrab) — Email test server for development.
 
 ### Encoding