It depends on how you send emails with MailBluster.
If you use MailBluster Managed SMTP, the SMTP sending cost is included in your Managed SMTP plan. You do not need a separate third-party SMTP account or pay a separate SMTP provider. Managed SMTP plans start at $17/month for 10,000 emails.
If you use Bring Your Own SMTP, SMTP fees are not included in your MailBluster pricing. These are billed separately by the SMTP you choose, such as Amazon SES, Mailgun, Postmark or SMTP2GO, based on their own pricing.