handle emails without a To: field

[codecov-commenter]

Codecov Report

Base: 69.72% // Head: 69.68% // Decreases project coverage by -0.03% :warning:

Coverage data is based on head (027f2a8) compared to base (ab599c5). Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #40 +/- ## ========================================== - Coverage 69.72% 69.68% -0.04% ========================================== Files 104 104 Lines 1612 1610 -2 ========================================== - Hits 1124 1122 -2 Misses 488 488 ``` | [Impacted Files](https://codecov.io/gh/Shroud-email/shroud.email/pull/40?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Shroud-email) | Coverage Δ | | |---|---|---| | [lib/shroud/email/parsed\_email.ex](https://codecov.io/gh/Shroud-email/shroud.email/pull/40?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Shroud-email#diff-bGliL3Nocm91ZC9lbWFpbC9wYXJzZWRfZW1haWwuZXg=) | `95.74% <ø> (ø)` | | | [lib/shroud/email/enricher.ex](https://codecov.io/gh/Shroud-email/shroud.email/pull/40?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Shroud-email#diff-bGliL3Nocm91ZC9lbWFpbC9lbnJpY2hlci5leA==) | `93.75% <100.00%> (-0.54%)` | :arrow_down: | | [lib/shroud/email/incoming\_email\_handler.ex](https://codecov.io/gh/Shroud-email/shroud.email/pull/40?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Shroud-email#diff-bGliL3Nocm91ZC9lbWFpbC9pbmNvbWluZ19lbWFpbF9oYW5kbGVyLmV4) | `93.33% <100.00%> (ø)` | | | [lib/shroud/email/outgoing\_email\_handler.ex](https://codecov.io/gh/Shroud-email/shroud.email/pull/40?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Shroud-email#diff-bGliL3Nocm91ZC9lbWFpbC9vdXRnb2luZ19lbWFpbF9oYW5kbGVyLmV4) | `85.71% <100.00%> (ø)` | | | [lib/shroud/email/spam\_handler.ex](https://codecov.io/gh/Shroud-email/shroud.email/pull/40?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Shroud-email#diff-bGliL3Nocm91ZC9lbWFpbC9zcGFtX2hhbmRsZXIuZXg=) | `96.29% <100.00%> (+0.14%)` | :arrow_up: | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Shroud-email). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Shroud-email)

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