Technically, you can use any SMTP Service.
However, Mailgun has the deepest integration into Growably allowing you to see much deeper email deliverability data inside your Growably Dashboard.
Note
If you’re not sure why you need to use an external SMTP Service with Growably, this article explains more.
If you don’t want to use Mailgun – then some others options are:
- SMTP2GO – a number of MSPs use this service and are happy with it
- SendGrid
- Amazon SES
- SendInBlue
- Any other SMTP Service you like
You can even use your own Gmail or Office365 account, however be careful as these services aren’t built for mass automated email sending so you may find some limitations & restrictions.