Macro for sending gmail

Sir

I need some help my problem is follows.

I have a data sheet. I will be updating every day the data sheet. I use a macro to generate a sheet with details of customers list who are due and their email address. Now I need a macro to send automatically e-mails (through my gmail account) to the customers emails, reminding them that there are dues and clear the dues.
All the data will be In the sheet itself hence by running the macro email should be dispatched thorough my gamil account.
Kindly help in this regard
with regards
Kishore