I have automated e-mail messages sent to my Gmail-based work account. I like to periodically remove the older messages as they clutter up any e-mail searching that I need to do. There are ways around this problem but getting rid of useless messages works best for me.
Here is the command to select the messages to delete. Type this in the message search box (don’t use the label operator if it does not apply to you):
label:servers before:2019-01-01
Explained: select all messages prior to January 1, 2019 that are labeled as “servers”.
Once you confirm the messages are the ones that you actually want to delete, click the box to select all of the messages displayed on the page, then click “Select all conversations that match this search”. Then just click the trash icon.
Below is a link that takes you to a Google page that describes the various Gmail search operators. If it is broken, just do a search for “Gmail search operators.”
https://support.google.com/mail/answer/7190?hl=en