The problem Coldmailer solves

This is a simple nodejs server that takes in the inputs and sends the mail using nodemailer. You set your own cover letter template first during setup and headline and it sends the mail to the given email address without opening mail app and no changes to format, just a few inputs. You can also attach your resumes to the mail. You can make different routes for different roles and different cover letter templates. Its just a basic utility application. If you have a list of emails and details, you can do them all at once, using a loop and an array of objects using minor tweeks to the code.

Challenges I ran into

Making it more customizable and robust.