customer sees this message while redirecting to

customer sees this message while redirecting to Paypal:

SMTP Error! Data not accepted.

SMTP server error: s3nl1k0031NZ3hZ01 :: auth :: Message rejected for spam or virus content :: Please include this entire message when contacting support :: v=2.0 cv=Jd4+XD2V c=1 sm=1 p=affgFaYOAAAA:8 a=dLadDjfzjplSizcHzwvmfQ==:17 a=YQlvzqm3q-kA:10 a=JngOO-ZOwbEA:10 a=l8ib2V92jg0A:10 a=H9cIMGdfPkEA:10 a=oo_aTJS2PzkA:10 a=vYMDNeyr1X8A:10 a=67yJwss3He-nmE7pFikA:9 a=QEXdDO2ut3YA:10 a=JBFWd0y1dTsA:10 a=AtCREw16dzgj0q5B:21 a=fdgAgiYxdWtdgJG_:21 a=wW6fLSMZup4CME1OGzEA:9 a=_W_S_7VecoQA:10 a=2rhXFDQNhL2Dx_zH:21 a=oqyg8hdzdnTS7kTP:21
SMTP Error! Data not accepted.

SMTP server error: s3nl1k0011NZ3hZ01 :: auth :: Message rejected for spam or virus content :: Please include this entire message when contacting support :: v=2.0 cv=LfS+G0ji c=1 sm=1 p=affgFaYOAAAA:8 a=dLadDjfzjplSizcHzwvmfQ==:17 a=0KQecaLA-nAA:10 a=l8ib2V92jg0A:10 a=HlqUn5SAI6kA:10 a=WHsXhg87phMA:10 a=69EAbJreAAAA:8 a=jBnCzreUXGYA:10 a=ylsHGJmhGOYobfe1ngUA:9 a=QEXdDO2ut3YA:10 a=yDntIn8Q230A:10 a=KHhNoJUavc6Kvl2d168A:9 a=_W_S_7VecoQA:10 a=tXsnliwV7b4A:10 a=5pTwqQz_wgVXX7rg:21 a=ZpZ6IBrx1ccRt6uX:21 a=0b4Sy6l4HvnC3Cpd:21 a=dL

Have you edited an email in HikaShop > System > Emails ?

I think that you are giving some data which is badly formatted.

No, just found out customers are not receiving confirmation emails or order created emails as well.