Follow the instructions below in order to reset the password in MassMailer.
Step 1:
Navigate to MassMailer app in Salesforce -> MassMailer Setup -> MassMailer Login
Make a note of the User Name, API Key.
![](https://s3.amazonaws.com/cdn.freshdesk.com/data/helpdesk/attachments/production/16042683499/original/8syHVT_XxmbjZ_RhjyIuTvp_jHKHGDsGWA.png?1564756100)
Step 2:
Reset the password in SendGrid by going to https://app.sendgrid.com/forgot_password
Step 3:
Make a note of the updated password in the previous step. Now go back to Salesforce. Navigate to the MassMailer app -> MassMailer Setup -> MassMailer Login.
Click on the Edit button; Enter the user name, password, and the API Key and Save.