Outlook and other email services have limits on the size of attachments you can use in emails. Outlook's attachment size limit is 20MB, while Gmail's attachment size limit is 25MB. When the file size to be sent exceeds the limit, sending files in email becomes difficult. Here's how to increase the Outlook attachment size limit.
How to increase Outlook attachment size limit
Step 1:
First, you access the Registry Editor on your computer. Then, depending on the version of Outlook you are installing and using on your computer, we access the path below.
Outlook 2010
HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\\Preferences
Outlook 2013
HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\\Preferences
Outlook 2016 and 2019
HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\\Preferences
Step 2:
Double-click the DWORD MaximumAttachmentSize file to adjust the attachment size limit in Outlook.
If you want to send a 28MB file, enter 29000 or 30000 in Valute data to send without any problems. In the Base section, we will select Decimal. Finally, click OK to save the settings.

Other ways to send large files on Outlook
If you want to send larger files to Outlook without making any deep system changes, you can upload the file to OneDrive and then attach the file link in an Outlook email. OneDrive allows you to share files up to 2GB in size. If the file is larger than 2GB, you will need to compress the file using file compression tools or compress it into multiple parts using a Zip editor.
You can also use free file sharing services with no file size limit. If you want to send larger files without compression, you can use services like ToffeeShare, UploadNow, FileTransfer, etc.