# 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/
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# What this PR does
* Allows to use multiple inbound email ESPs at the same time by setting
the `INBOUND_EMAIL_ESP` env variable to `amazon_ses,mailgun` for example
* Adds a new ESP `amazon_ses_validated` that performs SNS message
vaildation (`django-anymail` doesn't implement it:
[comment](35383c7140/anymail/webhooks/amazon_ses.py (L107-L108)))
## Which issue(s) this PR closes
Related to https://github.com/grafana/oncall-private/issues/2905
<!--
*Note*: If you want the issue to be auto-closed once the PR is merged,
change "Related to" to "Closes" in the line above.
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preface
each issue link with a [closing
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This ensures that the issue(s) are auto-closed once the PR has been
merged.
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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.
