Stop exceptions from raising when email has already been created

[andrewmcodes]

Type of PR

• [ ] feature
• [ ] enhancement
• [x] bug fix
• [ ] other

Description

We do not need to raise exceptions when emails cannot be created. This change also stops read marks from recording when a user is masquerading.

Fixes #1320

Checklist

• [x] My code follows the style guidelines of this project & the tests are passing
• [x] I have performed a self-review of my own code
• [x] I have requested a review from another developer(s)

[codecov[bot]]

Codecov Report

Merging #1321 into master will not change coverage. The diff coverage is 50.00%.

@@           Coverage Diff           @@
##           master    #1321   +/-   ##
=======================================
  Coverage   34.75%   34.75%           
=======================================
  Files         345      345           
  Lines        7990     7990           
=======================================
  Hits         2777     2777           
  Misses       5213     5213           

Impacted Files	Coverage Δ
app/controllers/emails_controller.rb	0.00% <0.00%> (ø)
app/mailboxes/incoming_mailbox.rb	64.28% <100.00%> (ø)
app/jobs/schedule_organization_report_job.rb	86.20% <0.00%> (ø)