To send a video, the most common way is to make use of the iMessage or SMS. For most users, this could be the simplest method - they just need to select the wanted videos from "Photos" App and then share the selected files with "Message". Hence, you can first select this way to transfer your iPhone videos.
Tutorial to share video from iPhone via messages:
Step 1. Unlock your iPhone and then access to your "Photos" App.
Step 2. Enter the album that contains the videos you wish to transfer and check the wanted files.
Step 3. Click on the "Share" icon and then a window with different options will pop up.
Step 4. Choose "Message" from the listed options and then select a contact as your recipient.
Step 5. Tap on "Send" to share the videos from your iPhone.
Different ways to email long videos on iPhone:
Step 1. Open "Photos" App and find out the videos that you want to transfer.
Step 2. Tap on "Share" and choose "Mail" from the listed options.
Step 3. Add the recipient and click on "Send".