Depending on your use case, you might want any emails sent via Solar Ladder to reflect your email address, see the following for reference:

Step 1: Go to Settings -> Profile and click on Connect Email Account for Sending Emails

Step 2: Click on Solar Ladder's Mail Servers
Step 3: Enter the email address and reply to email

Step 4: Click on Connect Email Account and your email should be linked.
You will receive an email from Postmark (Our Mail Server) at the mentioned address, please confirm it so email-sending from your address gets activated.

Now you can send proposal and invoice emails from your mentioned email address automatically to anyone from Solar Ladder's dashboard.
