A SMTP server is treating E-Mail from my program as if it was spam or the server rejects it with a 554 error.  I don't have any problems with Outlook.  How do I fix this?

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The reason this is occuring is because some spam filtering software is screening E-Mail for the "X-library:" header.  This header is sent by Indy 8.0 and the release versions of Indy 9.0.  In and of itself, this is not bad.  However, some malware such as spam bulk E-Mails and even a worm (W32/Nicehello@MM), were built with Indy meaning that they sent the same "X-Library:" header that most Indy-based E-Mail programs do.


For this reason, we have decided to remove the X-Library header from Indy 9.0 code and you can obtain it from our VCS.  Instructions are at:




If you are using Indy 8.0 and you can not upgrade to this code, you can remove the X-Library header by editing IdMessage and removing line 439 which reads:


Values['X-Library'] := gsIdProductName + ' ' + gsIdVersion ; {do not localize}


and then rebuild Indy using the FULL*.BAT file for your system.