Why do I not hear a sound when I send an email

JEC2 wrote:

When I send an email I do not hear a sound like I did previously. I have increased the volume and sent a couple of test messages to myself but still nothing.

Old issue, new issue, what changed?

Did you look at Mail >Preferences

Change General preferences in Mail on Mac - Apple Support

In addition to the previous post, check the settings in System Preferences->Sound->Sound Effects, specifically "Play user interface sound effects".

If this is off, I guess they are all off.