# What this PR does
Minor inbound email improvements:
* Adds SNS certificate caching (the [original JS
SDK](a6ba4d646d/index.js (L101-L104))
does that as well)
* Makes sure we see a 500 when OnCall can't fetch the certificate
## Which issue(s) this PR closes
Related to https://github.com/grafana/oncall-private/issues/2905
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## Checklist
- [x] Unit, integration, and e2e (if applicable) tests updated
- [x] Documentation added (or `pr:no public docs` PR label added if not
required)
- [x] Added the relevant release notes label (see labels prefixed w/
`release:`). These labels dictate how your PR will
show up in the autogenerated release notes.
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