if you want someone to help you with your question, you need to be more specific. Please tell us to what you are trying to attach something larger than 25 Mb.
I assume it is an email of some kind, but you need to tell us what email service and what email client you are using. Are you using web mail, Outlook, or Thunderbird, or whatever.
Different email services have different rules, but in general they all have limits on the size of attachments you are allowed to put onto an email message. This is a limit imposed for both practical and security reasons.
Imagine what happens when someone sends you an email with a 10 Gbyte attachment. Perhaps they did this by mistake. Perhaps they don't realize how long it takes to transfer that size of an attachment to the recipient's computer using a dialup line.
Who has a dialup line nowadays? Maybe not too many people, but there are still some. And, as I read many a number of the postings in this Forum, even if you have a "high speed" line from Rogers it may still take literally hours to download such a large attachment.
And what if someone is attempting a Denial of Service attack on your email? Then you can assume that they have purposely sent this huge attachment just to mess up someone else's email.
So, if you can provide further info, please do.
In conclusion, let me say that there are other and probably better ways to transfer large amounts of data than by email. Try something called ftp, or putting it on a USB stick or a CR-ROM, for example. There is snail mail, bicycle couriers and carrying it by hand, if need be. Although it is my understanding that global warming has made dog sleds obsolete as an option for this.
I apologize if I seem a little snarky on this issue, but please remember that the technology does have its limits, especially in Canada.
if its a rogers.com email, the limit per email is 25MB using webmail and 20MB using a pop client (e.g. outlook), thats just the way the cookies crumble. if you need to send larger files over the internet try other sources like yousendit.com etc.. keep in mind though that uploading a 500MB file will take a long time even on ultimate with its 2mpbs uploads.