从订阅者列表中删除订阅者
如果客户在您发给他们的电子邮件中点击取消订阅，或将该电子邮件标记为垃圾邮件，他们将会立即从您的列表中被自动删除。
如果某个电子邮件地址弹回，则该电子邮件地址不会包含在将来的电子邮件营销宣传活动中。
停止发送电子邮件
如果订阅者参与率较低，或存在其他保护您的发件人声誉并确保将来的电子邮件能够送达的负面影响指标，发送系统可能会停止发送电子邮件。
有多种因素可能会对电子邮件的效果产生负面影响。
列表质量和高跳出率
低质量的订阅者列表通常会导致高跳出率，这样反过来又会对电子邮件的送达率产生负面影响。
如果不正确的或不存在的电子邮件消息阻止消息送达，相应的电子邮件地址就会自动从订阅者列表中被删除。在导入电子邮件地址列表之前，请检查该地址列表并更正错别字或错误。
低打开率
发送电子邮件时，请选择对您的订阅者有意义的时间。您可以提前撰写电子邮件，然后安排电子邮件在您认为订阅者更有可能打开它的时间发送出去。
请验证电子邮件的主题行是否准确、简洁和引人注目。
大量取消订阅或经常被标记为垃圾邮件
如果订阅者手动将您的邮件标记为垃圾邮件，传送系统可能会停止传送您的邮件。如果收件人并未明确订阅过您的电子邮件营销，通常就会出现这种情况。请启用双重选择加入，以帮助确保订阅者想接收您的电子邮件。
Shopify商户官网原文详情：
Improving the quality of your subscriber list
Managing who does and who does not receive your email marketing is a good way to increase engagement, which in turn has an impact on the delivery and batching success rate of your emails. If you want to send email campaigns that are tailored to a specific set of customers, then you can create a customer segment. To edit individual customers profiles, click their name on the Customers page in your Shopify admin.
Remove a subscriber from your subscriber list
From your Shopify admin, click Customers.
Search for the customer, and then click the customer's name to open their profile.
In the Email Marketing section, click Edit status.
Uncheck Customer agreed to receive marketing emails.
Click Save.
If a customer clicks Unsubscribe in an email from you, or marks the email as spam, then they'll be automatically and immediately removed from your list.
If an email address bounces back, then that email address is not included in future email marketing email campaigns.
Emails stopped delivering
The delivery system might stop delivering an email message if subscriber engagement is low or if there are other negative performance indicators to protect your sender reputation and to ensure that future email messages are delivered.
There are several factors that might have a negative affect on an email's performance.
List quality and high bounce rates
Low-quality subscriber lists can often result in high bounce rates, which in turn have a negative impact on the deliverability of your emails.
When an incorrect or nonexistent email messages prevent a message from being delivered, then the corresponding email address is removed from the subscriber list automatically. Before you import a list of email addresses, review the address list and fix any typos or errors.
Low open rate
Send your emails at a time that makes sense for your subscribers. You can compose an email in advance, and then schedule the email to go out at a time that you think it's more likely to be opened by your subscribers.
Verify that the subject line of the email is accurate, concise, and compelling.
High number of unsubscribes or frequently flagged as spam
When subscribers manually mark your messages as spam, the delivery system might stop delivering your messages. This often occurs when the recipients didn't explicitly subscribe to your email marketing. Enable double opt-in to help ensure that your subscribers want to receive your emails.
文章内容来源：Shopify商户官方网站
