I have mixed results and have been using regex101.com for testing.

I ONLY want to grab a ticket number from a case and nothing else. The problem…AWS can’t standardize their ticket format so I have the following examples I need to be able to match. These come in email.

We have not heard back from you regarding case 183746574839201 in the last 7 days. We hope this means you have resolved your issue or question. If you need continued support, please contact us using the following URL

and

Amazon Web Services has opened case 383746574839201 on your behalf.

The details of your case are as follows:

Case ID: 383746574839201
Account ID: 948576647382
Subject: [Amazon GuardDuty Finding] Discovery:IAMUser/AnomalousBehavior - Finding Severity: Low
Severity: low