Before sending a file you should consider converting it, to reduce its size and the upload/download time, especially to prevent problems with large emails.
Tap and then Convert.
Converting a file creates a new file: choose the desired name or leave the default. Then select the target format.
The OGG format is similar to MP3 and offers a good compression ratio, suitable for emails.
The default quality should work in most cases. For speech, choose a lower quality to achieve high compression (smaller file).
Learn more about Recording formats
After conversion, the new file appears in the editor and the filename gets updated.
Tap to display a list of sharing options.
You may send you file by email, or share it by other means, depending on which third-party apps are installed (DropBox, etc..).