maximum number of emails sent

What is the MAXIMUM number of email addresses I can send - for a mass customer email?? (~ 2500)

eM Client has no limit, but there will be one from your email provider which varies depending on how you are sending the message.

Take GMail for example:

If all the addresses are in the To, CC or BCC field, there will be a limit of something like 500 recipients per message.

If you use eM Client’s mass mail feature, which sends a separate customized message to each recipient. Gmail personal accounts have a limit of something like 150 messages per day.