1==== external to internal, with extension 2|foo+extension@example.com| 3|foo bar+extension@example.com| 4|foo+ext+extension@example.com| 5==== external to internal, without extension 6|foo@example.com| 7|foo bar@example.com| 8|foo+ext@example.com| 9==== external to external, with extension 10|foo+extension@example.com| 11|"foo bar+extension"@example.com| 12|foo+ext+extension@example.com| 13==== external to external, without extension 14|foo@example.com| 15|"foo bar"@example.com| 16|foo+ext@example.com| 17==== internal to internal, with extension 18|foo+extension@example.com| 19|foo+ext+extension@example.com| 20==== internal to internal, without extension 21|foo@example.com| 22|foo+ext@example.com| 23