Is it possible to delete extended properties without knowing the id?

Hello,

Can you delete any custom extended properties without knowing their ID?

I took over managing a feature that used EWS to send emails to customers.The current code creates a new GUID, and thus new Extended Property, every time an email is sent.

// Create a custom extended property and add it to the message. 
var myExtendedPropertyDefinition = new ExtendedPropertyDefinition(Guid.NewGuid(), "MyGuidId", MapiPropertyType.String);

mail.SetExtendedProperty(myExtendedPropertyDefinition, "MyGuidId"); 

// Send and save a copy
mail.SendAndSaveCopy();

Thank you