🎉 Add Mailmate

[johnkree]

🪩 Provide a link to the proposed addition

https://freron.com

😳 Explain why it should be added

Mailmate is one of the strongest Mail clients for Mac. It has Spam Sieve integrated and has a very powerful tagging and search function. Nothing matches Mailmate's search.

📖 Additional context

No response

🧨 Issue Checklist

• I have checked for other similar issues
• I have explained why this change is important
• I have added necessary documentation (if appropriate)