My messages are coming with “https://s3.amazonaws.com/msv5/images/spacer.gif” added to them which is causing error messages with https://www.mail-tester.com/. There is no use of a spacer.gif in the original message, no reference to one in the phpList footer. Any idea where this is coming from??? Thanks!!
@Marcus see this earlier topic [SOLVED] Not seeing views or unique views in 3.3.3 - #3 by BaliDave
In that case mailscanner was removing the phplist user tracking pixel.
Ok that makes sense. Thanks!