Features: 

• Create and modify groups of address book contacts.

• Assign contacts to groups (single and fast assigning) .

• Create and modify mailing lists for mass emails.

• Search for names, phone numbers, email addresses, postal addresses, departments and notes within all contacts.

• Create and modify contacts.

• Print single or multiple contacts.

• Export contacts to Excel or CSV file.

• Compatible also with macOS 10.12 (Sierra).

• And more 

Mailing lists:

• Usable within GroupsPro for sending emails to several recipients.

• Add text and photos.

• Cc and Bcc recipients partially supported.

• Attachments.

• PDF as images or attachments.

• Message as HTML possible.

• Send prepared emails manually with the Mail app.

Compatibility: macOS 10.13 or later

Mac App Store: https://geo.itunes.apple.com/app/id876504539