使用Python win32com读取Outlook邮件遇数字标识符错误求助

云上老周

2026-7-8

问题：遍历本地Outlook邮件时触发数字标识符安全错误

我用WinPython搭配MS Office 2019（Outlook）编写代码统计未发送邮件的工作日，代码如下：

import win32com.client
import datetime

# Create an instance of Outlook
outlook = win32com.client.Dispatch("Outlook.Application").GetNamespace("MAPI")

# Access the inbox folder
inbox = outlook.GetDefaultFolder(5).Items

# Set to store sent dates
sent_dates = set()
start_date = datetime.date(2022, 1, 1)
end_date = datetime.date(2023, 1, 1)

i = 0
for email in inbox:
    if email.Class == 43 and email.SentOn.date() >= start_date and email.SentOn.date() <= end_date:
        sent_dates.add(email.SentOn.date())
    print("Email", i)
    i += 1

# Create a range of dates within the specified date range
date_range = set(
    datetime.date.fromordinal(day) for day in range(
        start_date.toordinal(), end_date.toordinal() + 1
    )
)

# Exclude weekends (Saturday and Sunday)
date_range = {
    date for date in date_range if date.weekday() not in [5, 6]
}

# Find the workdays when you didn't send emails
workdays_without_emails = date_range - sent_dates

# Print workdays without sent emails
print("Workdays without sent emails:")
for day in sorted(workdays_without_emails):
    print(day)

当本地仅存储1年邮件时代码正常运行，但下载2年邮件后，遍历到约6600封邮件时触发以下错误：

Traceback (most recent call last):
  File "C:\Users\xxxx\Downloads\WPy64-31150\scripts\outlook2.py", line 13, in <module>
    if correo.Class == 43 and correo.SentOn.date() >= start_date and correo.SentOn.date() <= end_date:
  File "C:\Users\xxxx\Downloads\WPy64-31150\python-3.11.5.amd64\Lib\site-packages\win32com\client\dynamic.py", line 627, in __getattr__
    ret = self._oleobj_.Invoke(retEntry.dispid, 0, invoke_type, 1)
pywintypes.com_error: (-2147352567, 'An exception occurred.', (4096, 'Microsoft Outlook', 'The underlying security system cannot find the name of the digital identifier.', None, 0, -2146893792), None)

再次运行时，遍历到6627封邮件时触发同样错误：

Email 6624
Email 6625
Email 6626
Email 6627
Traceback (most recent call last):
  File "C:/Users/xxx/Downloads/WPy64-31150/scripts/outlook3.py", line 17, in <module>
    if email.Class == 43 and email.SentOn.date() >= start_date and email.SentOn.date() <= end_date:
  File "C:\Users\xxx/Downloads\WPy64-31150\python-3.11.5.amd64\Lib\site-packages\win32com\client\dynamic.py", line 627, in __getattr__
    ret = self._oleobj_.Invoke(retEntry.dispid, 0, invoke_type, 1)
pywintypes.com_error: (-2147352567, 'An exception occurred.', (4096, 'Microsoft Outlook', 'The underlying security system cannot find the name of the digital identifier.', None, 0, -2146893792), None)

解决建议

捕获异常跳过加密/签名邮件：错误由加密或数字签名邮件触发，读取这类邮件属性时会触发安全验证失败。在循环中加入异常捕获，跳过此类邮件：
先在顶部导入pywintypes，再修改循环代码：

import win32com.client
import datetime
import pywintypes  # 新增导入

# ... 其他代码保持不变 ...

i = 0
for email in inbox:
    try:
        if email.Class == 43 and email.SentOn.date() >= start_date and email.SentOn.date() <= end_date:
            sent_dates.add(email.SentOn.date())
        print("Email", i)
        i += 1
    except pywintypes.com_error as e:
        # 匹配数字标识符相关错误码，跳过当前邮件
        if -2146893792 in e.args[2]:
            print(f"跳过异常邮件 {i}: 数字标识符验证失败")
            i += 1
            continue
        # 其他类型错误重新抛出
        raise

切换到已发送邮件文件夹遍历：当前代码遍历收件箱，但统计发送日期应直接访问已发送邮件文件夹（默认编号为6），减少无效邮件遍历，同时避开收件箱中的加密邮件：
修改获取文件夹的代码：
```
# 替换原来的inbox代码，访问已发送邮件文件夹
sent_items = outlook.GetDefaultFolder(6).Items
```
后续循环遍历sent_items即可，逻辑更精准，处理邮件量大幅减少。

提前过滤日期范围优化性能：在遍历前用Outlook的Restrict方法过滤目标日期内的邮件，减少循环次数：

sent_items = outlook.GetDefaultFolder(6).Items
sent_items.Sort("[SentOn]", True)
sent_items.IncludeRecurrences = True
# 构造Outlook格式的日期过滤字符串
filter_str = f"[SentOn] >= '{start_date.strftime('%m/%d/%Y')}' AND [SentOn] <= '{end_date.strftime('%m/%d/%Y')}'"
filtered_items = sent_items.Restrict(filter_str)

之后遍历filtered_items即可，只处理符合日期要求的邮件。

清理Outlook数字证书缓存：打开Outlook，依次进入文件→选项→信任中心→信任中心设置→电子邮件安全→数字标识，删除无效或过期的证书，重启Outlook后再运行代码。

内容的提问来源于stack exchange，提问作者Carlos

使用Python win32com读取Outlook邮件遇数字标识符错误求助

解决建议 #

解决建议