In the list of notification profiles you can configure to receive alerts in OpManager, you will find that there are two options to receive alerts via SMS. They are
The Email to SMS option is a feature that allows you to convert a standard email into an SMS message. You can understand this process in 3 simple steps.
Now, you are all set to receive Email based SMS notifications.
The SMS option allows you to receive a regular text message when an alert is raised based on the criteria configured into the SMS notification profile. The process is very simple.
Now, you are all set to receive SMS notifications. To know more about configuring your gateway, click here.
Email based SMS converts Emails into SMS messages. For example, OpManager sends an email to your SMS service provider (firstname.lastname@example.org). They will convert your Email alert into an SMS compatible format and will push the notification to your intended recipient. This is not the case with SMS as there is no conversion involved and the alert is directly pushed as a text message.