邮件事件类型
在发送邮件时，并不能保证一定能送达，例如对方邮箱已满、收件人地址不存在、对方将邮件标记成SPAM等。根据不同的事件类型，可以分类如下：
Bounce - 退回
bounce分为两种：
- Hard bounce - 例如邮件地址不存在。SES不会重试
hard bounce - Soft bounce - 临时发送失败。例如对方邮箱满了，或者连接超时。SES会重试发送几次
soft bounce。
如果邮件发送失败，可以配置SES通知到SNS。
Complaint - 投诉
大多数电子邮件客户端程序都提供一个标记为“标记为垃圾邮件”或类似按钮，可将邮件移动到垃圾邮件文件夹，并将其转发给电子邮件提供商。 此外，大多数电子邮件提供商都会维护一个滥用地址（例如，abuse@example.net），用户可以在其中转发不需要的电子邮件并请求电子邮件提供商采取措施阻止它们。 在这两种情况下，收件人都会提出complaint。 如果电子邮件提供商认定你是垃圾邮件发送者，并且SES 与电子邮件提供商设置了反馈循环，则电子邮件提供商会将投诉发送回SES。 当SES 收到此类投诉时，它会通使用SNS通知等方式将complaint事件转发给你，具体取决于设置的方式。
Bounce Rate与Complaint Rate
AWS 执行严格的法规，来检查发件人声誉。 两个关键指标有助于追踪这种声誉：
Bounce Rate
临时问题会导致软退回（例如，收件人邮箱已满），而永久性问题会导致硬退回（例如，收件人地址无效）。
- 如果Bounce Rate超过 5%，AWS 将审核你的 SES 账户。
- 如果Bounce Rate超过 10%，将被禁止发送电子邮件。
Complaint Rate
当收件人手动将您的电子邮件标记为垃圾邮件时，就会发生这些事件。
- 如果您的投诉率超过 0.1%，AWS 将审核 SES 账户。
- 如果您的投诉率超过 0.5%，将被禁止发送电子邮件，直至进一步调查。
如何排查bounce率过高或bounce的具体原因
确定导致退回率增加的原因，可以查看 SNS 退回通知或事件数据中的 bounceType 和 diagnosticCode 字段。我们将在下一章仔细讨论。具体参考退回类型
| bounceType | bounceSubType | Description |
|---|---|---|
Undetermined |
Undetermined |
Amazon SES was unable to determine a specific bounce reason. |
Permanent |
General |
Amazon SES received a general hard bounce. If you receive this type of bounce, you should remove the recipient’s email address from your mailing list. |
Permanent |
NoEmail |
Amazon SES received a permanent hard bounce because the target email address does not exist. If you receive this type of bounce, you should remove the recipient’s email address from your mailing list. |
Permanent |
Suppressed |
Amazon SES has suppressed sending to this address because it has a recent history of bouncing as an invalid address. To override the global suppression list, see Using the Amazon SES account-level suppression list . |
Permanent |
OnAccountSuppressionList |
Amazon SES has suppressed sending to this address because it is on the account-level suppression list . This does not count toward your bounce rate metric. |
Transient |
General |
Amazon SES received a general bounce. You may be able to successfully send to this recipient in the future. |
Transient |
MailboxFull |
Amazon SES received a mailbox full bounce. You may be able to successfully send to this recipient in the future. |
Transient |
MessageTooLarge |
Amazon SES received a message too large bounce. You may be able to successfully send to this recipient if you reduce the size of the message. |
Transient |
ContentRejected |
Amazon SES received a content rejected bounce. You may be able to successfully send to this recipient if you change the content of the message. |
Transient |
AttachmentRejected |
Amazon SES received an attachment rejected bounce. You may be able to successfully send to this recipient if you remove or change the attachment. |
例如我们往gmail邮箱里过高频率的发送同一标题邮件，会触发gmail的bounce：
https://repost.aws/zh-Hans/knowledge-center/ses-high-bounce-rate
https://repost.aws/zh-Hans/knowledge-center/ses-bounce-notifications-sns