使用exchangelib发送O365邮件遇ErrorNonExistentMailbox错误求助

在使用Python的exchangelib库从O365用户邮箱发送邮件时，遇到以下错误：

exchangelib.errors.ErrorNonExistentMailbox: The SMTP address has no mailbox associated with it

使用的代码如下：

credentials = Credentials(username='username', password='password')
my_account = Account(primary_smtp_address="my organization email address",
                     config=Configuration(
                         credentials=credentials,
                         service_endpoint='https://test/EWS/Exchange.asmx',
                         auth_type='NTLM',                            
                         # server='outlook.office365.com'
                     ),
                     autodiscover=False, access_type=DELEGATE)


m = Message(account=my_account
            , folder=my_account.sent
            , subject=e_subject
            , body=HTMLBody(e_body)
            , to_recipients=[Mailbox(email_address='email address')])

m.send_and_save()

可能的解决办法 #

• 修正EWS服务端点：当前代码中的service_endpoint是无效的测试地址，O365官方的EWS端点为https://outlook.office365.com/EWS/Exchange.asmx，替换后可确保连接到正确的Exchange服务器。
• 验证收件人邮箱有效性：确认to_recipients中的邮箱地址拼写正确，且该邮箱确实存在（内部邮箱需在O365组织内，外部邮箱需是有效的公共邮箱）。
• 检查账号与邮箱匹配性：确保primary_smtp_address填写的是与credentials对应的有效组织邮箱，无拼写错误。
• 调整认证与权限配置：O365优先推荐OAuth2认证，若使用NTLM需确保账号拥有EWS访问权限；同时确认access_type设置合理——若使用自身账号发件，IMPERSONATION或DELEGATE需对应正确的权限配置。
• 启用自动发现（可选）：若不确定端点配置，可将autodiscover=True并注释手动config，让exchangelib自动获取O365的服务端点，避免手动配置错误。

修改后的示例代码 #

from exchangelib import Credentials, Account, Message, HTMLBody, Configuration, DELEGATE

# 替换为实际的账号信息
credentials = Credentials(username='your_org_username', password='your_password')
config = Configuration(
    credentials=credentials,
    service_endpoint='https://outlook.office365.com/EWS/Exchange.asmx',
    auth_type='NTLM'
)

# 替换为实际的组织邮箱地址
my_account = Account(
    primary_smtp_address="your_org_email@domain.com",
    config=config,
    autodiscover=False,
    access_type=DELEGATE
)

# 替换为有效的收件人邮箱
m = Message(
    account=my_account,
    folder=my_account.sent,
    subject=e_subject,
    body=HTMLBody(e_body),
    to_recipients=[Mailbox(email_address='valid_recipient@domain.com')]
)

m.send_and_save()

内容的提问来源于stack exchange，提问作者Endraja Dhage