ERROR - execution expired

[crazzybat]

I sent a test email, and I was greeted with:

‘ERROR - execution expired (email)’
I am using MailGun for SMTP emails. Port 587

First i don’t know how to fix, so can please help me with this?

Second I read this

ERROR - execution expired (email)

In /admin I see this prompt for the first time: There are 91 email jobs that failed. Check your app.yml and ensure that the mail server settings are correct. See the failed jobs in Sidekiq. I sent a test email, and I was greeted with: ERROR - execution expired (email) I am using Brevo for SMTP email. I went ahead and double checked my app.yml to ensure that my settings were correct, and they are. I have rebuilt a few times now, and even shut off the server and turned it back on. Nothing is …

and we hosting on digital ocean, in their official guide mentioned about SMTP ports 25, 465, and 587 are blocked on Droplets to prevent spam and other abuses of our platform. Source

To send mail from DigitalOcean, we recommend using SendGrid via the SendGrid Marketplace 1-Click App.

So can you please provide me guide from here to fix the problem?
Thank you for reading…