It's 6pm Friday. Your 80MB PDF needs to reach the client tonight. Your email server bounced it. Your client doesn't use the shared drive. WeTransfer is blocked at their end.
Splitting into three 25MB attachments is the path of least resistance. Flint by size does it in 30 seconds.
Try compression first (5 seconds)
Drop the file into compress PDF before resorting to splits. An 80MB PDF dominated by scanned pages will often shrink to 20MB without visible loss. If compression alone gets you under the limit, send one file. Splitting is a fallback, not the first move.
If compression isn't enough, split by size
Open split PDF, choose 'split by size', enter '24' MB (under Gmail's 25MB cap for safety). Flint produces 3-4 files. Each is under the limit. Each opens as a normal PDF. Name them clearly: 'Annual-Report-Part-1-of-3.pdf' and so on.
Send in one email when possible
Three attachments in one email is better than three separate emails — easier for the recipient to find them. If total exceeds the email's combined attachment limit, send a couple per email with clear subject lines: '(1/2) Annual Report' and '(2/2) Annual Report'.
Tell the recipient how to reassemble
Most recipients won't bother. But if they need a single file (printing, archival), tell them to merge PDFs at Flint — drag, click, done. Or just send them a link to your file share once Monday hits.
FAQ
Why not just attach a link?
Best option when available. Use SharePoint, Drive, Dropbox if your org permits. Splitting is for when links aren't an option.
Does each split open correctly on its own?
Yes. Each is a complete, standalone PDF.
What about page numbers across splits?
Each split keeps its original page labels. Part 2 starts at the page number it had in the source file.
Outlook size limits?
Most are 20-25MB. Some enterprise Exchange instances cap at 10MB. Match Flint's setting to your actual limit.
Compress first, split if needed, send. Split for email.