Admin email doesn't send everything

I have a custom form with a checkbox tied to a statement that a donor must agree to before sending their donation.
When a donation is sent this agreement appears in the email to the admin, but only the first half of it is shown and everything else is truncated or missing.

How can I increase the character or word limit of what is sent by email to the administrator?

Thanks in advance.

Hi
That is really strange. Could you submit a support ticket contains your site information so that I can check it for you ?
Thanks ,
Tuan

Thanks for the reply Tuan. I submitted a ticket.

Ok . I will check it and reply you within few hours . I am abit busy at the moment to finish a project .

Thanks ,
Tuan

It's been more than a few hours now, but I completely understand.

Take your time. I appreciate whatever help you are able to give.

Hi
Thanks so much for understanding. I was busy with something today and haven't had time to look at the issue for you yet (To be honest, been busy with developing new version of the extension) .

I promise I will check it for you on tomorrow morning .

Thanks,
Tuan