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用在ESA的一个文本消息替换一个剥离的附件

2016 年 10 月 25 日 - 机器翻译
其他版本: PDFpdf | 英语 (2015 年 8 月 22 日) | 反馈

简介

本文描述如何用在电子邮件安全工具(ESA)的一个文本消息替换一个剥离的附件。

贡献用斯科特勒德和恩里科沃纳, Cisco TAC工程师。

创建消息过滤器

当他们剥离附件时,许多站点希望提供其他信息。您能用消息过滤器执行此,允许一个可选注解栏的包括。

这是示例消息过滤器:

    StripInboundMP3s:
    if (recv-listener == "InboundMail") {
      drop-attachments-by-filetype ('mp3', 'Corporate policy disallows mp3
attachments.  Please contact the helpdesk at x411 for assistance in
transferring binary files.');
    }

您能创建在CLI的此消息过滤器用过滤器命令:

    smtp.example.com> filters

    Choose the operation you want to perform:
    - NEW - Create a new filter.
    - DELETE - Remove a filter.
    - IMPORT - Import a filter script from a file.
    - EXPORT - Export filters to a file
    - MOVE - Move a filter to a different position.
    - SET - Set a filter attribute.
    - LIST - List the filters.
    - DETAIL - Get detailed information on the filters.
    - LOGCONFIG - Configure log subscriptions used by filters.
    - ROLLOVERNOW - Roll over a filter log file.
    []> new

    Enter filter script.  Enter '.' on its own line to end.
    StripInboundMP3s:
    if (recv-listener == "InboundMail") {
      drop-attachments-by-filetype ('mp3', 'Corporate policy disallows mp3 attachments. 
Please contact the helpdesk at x411 for assistance in transferring binary files.');
    }
    .
    1 filters added.

    Choose the operation you want to perform:
    - NEW - Create a new filter.
    - DELETE - Remove a filter.
    - IMPORT - Import a filter script from a file.
    - EXPORT - Export filters to a file
    - MOVE - Move a filter to a different position.
    - SET - Set a filter attribute.
    - LIST - List the filters.
    - DETAIL - Get detailed information on the filters.
    - LOGCONFIG - Configure log subscriptions used by filters.
    - ROLLOVERNOW - Roll over a filter log file.
    []>

    smtp.example.com> commit

    Please enter some comments describing your changes:
    []> add StripInboundMP3s filter

    Changes committed: Wed Nov 24 18:32:03 2004 MST

您能也使用消息过滤器操作作用变数为了提供更多信息,例如时间戳或发送方。

创建通知消息

另一方法将传送解释策略的分开的通知消息。此的优点是您能创建更加长和更多详细信息,并且您能也发送它到发送方、收件人,或者您希望通知的其他地址。

为了创建通知消息,请使用CLI命令的textconfig

    smtp.example.com> textconfig

    Current Text Resources:
    1. Disclaimer (Message Footer)
    2. attach.size.notify (Notification Template)

    Choose the operation you want to perform:
    - NEW - Create a new text resource.
    - IMPORT - Import a text resource from a file.
    - EXPORT - Export text resource to a file.
    - PRINT - Display the content of a resource.
    - EDIT - Modify a resource.
    - DELETE - Remove a resource from the system.
    []> new

    What kind of text resource would you like to create?
    1. Message Footer
    2. Notification Template
    [1]> 2

    Please create a name for the notification template:
    []> mp3.strip.notify

    Enter the encoding for the notification template:
    1. US-ASCII
    2. Unicode (UTF-8)
    3. Unicode (UTF-16)
    4. Western European/Latin-1 (ISO 8859-1)
    5. Western European/Latin-1 (Windows CP1252)
    6. Traditional Chinese (Big 5)
    7. Simplified Chinese (GB 2312)
    8. Simplified Chinese (HZ GB 2312)
    9. Korean (ISO 2022-KR)
    10. Korean (KS-C-5601/EUC-KR)
    11. Japanese (Shift-JIS (X0123))
    12. Japanese (ISO-2022-JP)
    13. Japanese (EUC)
    [1]>

    Enter or paste the notification template here.  Enter '.' on a blank line to end.
    To whom it may concern:

    You have attempted to send an MP3 file to a corporate address.  It is against
    corporate policy to send or receive MP3 files, and the MP3 was stripped
    from the message you sent.  The other parts of the message were
    delivered to the recipient.

    If you have any problems or questions regarding this policy, please contact
    the Help Desk at x411 or 800-555-1212.

    Thank you for your attention to this matter.
    Corporate Management
    .

    Notification template "mp3.strip.notify" created.

    Current Text Resources:
    1. Disclaimer (Message Footer)
    2. attach.size.notify (Notification Template)
    3. mp3.strip.notify (Notification Template)

    Choose the operation you want to perform:
    - NEW - Create a new text resource.
    - IMPORT - Import a text resource from a file.
    - EXPORT - Export text resource to a file.
    - PRINT - Display the content of a resource.
    - EDIT - Modify a resource.
    - DELETE - Remove a resource from the system.
    []>

    smtp.example.com> commit

    Please enter some comments describing your changes:
    []> create mp3.strip.notify for notifications

    Changes committed: Wed Nov 24 18:52:32 2004 MST

通知操作发送消息的一概略的电子邮件对指定的电子邮件地址。通知摘要包含信封地址的内容,消息的信息标题和匹配消息消息过滤器的名称。使用此的消息过滤器通知模板类似于此:

    StripInboundMP3s:
    If (recv-listener == "InboundMail")
    AND (attachment-filetype == "mp3") {
      drop-attachments-by-filetype("mp3");
      notify("$EnvelopeSender,$EnvelopeRecipients", "[$FilterName] MP3s not allowed",
"$EnvelopeSender", "mp3.strip.notify");
    }

注意:规则当前检查消息是否有一个mp3附件在剥离和发送通知前。

此通知消息传送到发送方和收件人,当标题栏[StripInboundMP3s] MP3s没允许;它设置返回路径,默认为邮件发送系统MAILER-DAEMON@smtp.example.com,为发送方。消息有mp3.strip.notify消息加上以前注释的通知消息的内容。

是谨慎的关于通知发送方。因为多数电子邮件是垃圾邮件,一个消息过滤器例如描述的一previoulsy生成是典型地无法投递的通知发送消息到新闻组和病毒发送方。过滤器可能也创建,内容过滤器。内容过滤器在反垃圾邮件以后应用,并且抗病毒处理消息。只有当丢弃垃圾邮件和病毒附件,通知在内容过滤器的发送方比在消息过滤器,但是更加合理的。



Document ID: 117867