email software; email program; mail client
Refers to applications used for sending, receiving, and managing email, such as Outlook, Thunderbird, or Apple Mail.
I installed a new email program.
This email software has an excellent spam filter.
Variant with a middle dot; less common in everyday writing but seen in technical contexts.
Wasei-eigo (Japanese-made English) combining メール (mail) and ソフト (software).