确定 System.Net.Mail.SmtpClient.Send 结果

Question

我试图使用枚举总结 System.Net.Mail.SmtpClient.Send 的结果。这样我就知道是否应该重试发送电子邮件并希望防止发送重复的电子邮件。

public enum MailSendStatus {
    None,
    Sent,
    ErrorCannotSend,
    TryAgain,
    SentMaybe
}

我已捕获来自 Send 的所有异常，并从 http://msdn.microsoft.com/en-us/library/system.net.mail.smtpstatuscode(v =vs.80).aspx。分解看起来正确吗？或者有更好的方法来做到这一点吗？

try {
    smtp.Send(msg);
} catch (ArgumentNullException e) {
    return MailSendStatus.ErrorCannotSend;
} catch (ObjectDisposedException e) {
    return MailSendStatus.ErrorCannotSend;
} catch (InvalidOperationException e) {
    return MailSendStatus.ErrorCannotSend;
} catch (SmtpFailedRecipientsException e) {
    return MailSendStatus.ErrorCannotSend;
} catch (SmtpException e) {
    switch(e.StatusCode) {
        case SmtpStatusCode.BadCommandSequence:
        case SmtpStatusCode.MailboxNameNotAllowed:
        case SmtpStatusCode.HelpMessage:
        case SmtpStatusCode.SyntaxError:
        case SmtpStatusCode.SystemStatus:
            return MailSendStatus.ErrorCannotSend;
        case SmtpStatusCode.CannotVerifyUserWillAttemptDelivery:
        case SmtpStatusCode.UserNotLocalWillForward:
            return MailSendStatus.SentMaybe;
        case SmtpStatusCode.ClientNotPermitted:
        case SmtpStatusCode.CommandNotImplemented:
        case SmtpStatusCode.CommandParameterNotImplemented:
        case SmtpStatusCode.CommandUnrecognized:
        case SmtpStatusCode.ExceededStorageAllocation:
        case SmtpStatusCode.GeneralFailure:
        case SmtpStatusCode.InsufficientStorage:
        case SmtpStatusCode.LocalErrorInProcessing:
        case SmtpStatusCode.MailboxBusy:
        case SmtpStatusCode.MailboxUnavailable:
        case SmtpStatusCode.MustIssueStartTlsFirst:
        case SmtpStatusCode.ServiceClosingTransmissionChannel:
        case SmtpStatusCode.ServiceNotAvailable:
        case SmtpStatusCode.ServiceReady:
        case SmtpStatusCode.StartMailInput:
        case SmtpStatusCode.TransactionFailed:
        case SmtpStatusCode.UserNotLocalTryAlternatePath:
            return MailSendStatus.TryAgain;
        case SmtpStatusCode.Ok:
            break;
    }
} catch (Exception e) { 
    return MailSendStatus.SentMaybe;
}
return MailSendStatus.Sent;

Answer 1

catch (ArgumentNullException e) {    return MailSendStatus.ErrorCannotSend;} catch 
(ObjectDisposedException e) {    return MailSendStatus.ErrorCannotSend;} catch 
(InvalidOperationException e) {    return MailSendStatus.ErrorCannotSend;

我不喜欢这个。 ArgumentNull、ObjectDispose 是编程错误（InvalidOperation 也是如此）。您不应将它们分解为 SMTP 错误，而应将其修复。因此，让程序崩溃是件好事（并输出堆栈跟踪）。方法是“快速失败”。不要重新抛出您不知道如何处理的异常，InvalidOperationException、ObjectDisposeException 表示状态有问题，ArbumentNullException 是用法/ui 错误。