It says my email max for attachments is 28.3 MB - That can't be correct

the size limit on direct outgoing iCloud email messages is: 20 MB.

In some cases, you can reduce the file size by Zip-ing it

Compress or uncompress files and folders on Mac - Apple Support

if already Zipped, Zipping again tends to make it bigger or about the same.

if running 10.10 Yosemite or later, you can use FileDrop to get your message through a little bit differently. if your file were ever-so slightly larger, it would have been offered as an option.

Mail Drop limits - Apple Support

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Mail does mail-like things sorta-kinda okay, but mail is bad at a whole lot of things including file transfer, knowledge transfer, information storage and retrieval, sharing and distributing arriving an organization’s support activities, and then there’s all the spam of course. Major providers are making mail incrementally less tractable, too.

As an alternative to transferring big files via mail, iCloud can make files and directories public:

Share files and folders in iCloud Drive on iCloud.com - Apple Support

Those limits are generally set individually by your Email service provider, and could also be based on the remaining email storage space on that specific email account.