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how_to:data_stream_contained_nul_character [2015/12/22 17:35] – paul | how_to:data_stream_contained_nul_character [2016/05/11 09:40] – [Description of the problem] paul | ||
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======Data stream contained NUL character====== | ======Data stream contained NUL character====== | ||
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+ | =====Description of the problem===== | ||
NUL characters (bytes with value 0) are not allowed in email messages and should not be transmitted over POP3, SMTP or IMAP4 except in certain circumstances. If an attachment contains such a byte it must be encoded using //Base64// or // | NUL characters (bytes with value 0) are not allowed in email messages and should not be transmitted over POP3, SMTP or IMAP4 except in certain circumstances. If an attachment contains such a byte it must be encoded using //Base64// or // | ||
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For incoming SMTP, VPOP3 will reject a message that contains a NUL character and the sender should receive a delivery failure report. This is the correct thing to do when receiving an invalid message. | For incoming SMTP, VPOP3 will reject a message that contains a NUL character and the sender should receive a delivery failure report. This is the correct thing to do when receiving an invalid message. | ||
- | For incoming POP3, VPOP3 will not download the message, it will report an error message to the administrator, | + | For incoming POP3, VPOP3 will not download the message, it will report an error message to the administrator, |
So, the ideal solution would be for the upstream mail server to sort the problem out, as the problem is coming from there (they should either reject the message, or recode the message to base64 or quoted-printable encoding). | So, the ideal solution would be for the upstream mail server to sort the problem out, as the problem is coming from there (they should either reject the message, or recode the message to base64 or quoted-printable encoding). | ||
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+ | =====Changing how VPOP3 handles the invalid characters===== | ||
If that is not possible, then you can make VPOP3 handle the problem differently. VPOP3 can either remove the nul character totally, or replace it with a specified character (eg a space or question mark) | If that is not possible, then you can make VPOP3 handle the problem differently. VPOP3 can either remove the nul character totally, or replace it with a specified character (eg a space or question mark) | ||
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+ | ====Version 6.17 or later==== | ||
+ | In the VPOP3 settings go to Settings -> Misc Settings -> Advanced and set the **NULL characters in POP3 downloads** option as you wish. | ||
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+ | ====Version 6.16 or earlier==== | ||
To do this for POP3 collection (the usual time it is needed) go to a command prompt in the VPOP3 directory and run: | To do this for POP3 collection (the usual time it is needed) go to a command prompt in the VPOP3 directory and run: | ||
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Set the < | Set the < | ||
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+ | **Note:** you should use VPOP3 v6.16 or later if possible. Earlier versions had a bug which meant this setting did work in every situation. | ||
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- | Keywords: null character | + | Keywords: null character |