Can I send email or text marketing messages to my clients?

Yes this feature Existing at Expandcart 

You can use this feature by going from the control panel to the marketing then campaigns ... Then there are two taps at the top, which are MAIL and SMS through which you can choose one of them and then go to tap TO and choose the appropriate menu which includes many options ... then the name of the subject is written in the Subject ... and then the text you written at the Message and press send

This is for sending mail ... Next image for clarification

Regarding the settings of SMS , only the TO tap and the text of the Message ...

Next picture for clarification