Simplify `SmtpData`.
Simplify `SmtpData`.

github/codeql-go,github/codeql-go,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql-go,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql-go,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql