[X4U] Rejected mail

[Al Grappone]

Last couple of days Windows hot mail has rejected mail I have sent  
from Apple mail.
Shows lines of example:

uwUAALwFAAC9BQAAvgUAAL8FAADABQAAwQUAAMIFAADDBQAAxAUAAMUFAADGBQAAxwUAAMgFAADJ
BQAAygUAAMsFAADMBQAAzQUAAM4FAADPBQAA0AUAANEFAADSBQAA0wUAANQFAADVBQAA1gUAANcF
AADYBQAA2QUAANoFAADbBQAA3AUAAN0FAADeBQAA3wUAAOAFAADhBQAA4gUAAOMFAADkBQAA5QUA
AOYFAADnBQAA6AUAAOkFAADqBQAA6wUAAOwFAADtBQAA7gUAAO8FAADwBQAA8QUAAPIFAADzBQAA
9AUAAPUFAAD2BQAA9wUAAPgFAAD5BQAA+gUAAPsFAAD8BQAA/QUAAP4FAAD/ 
BQAAAAYAAAEGAAAC
BgAAAwYAAAQGAAAFBgAABgYAAAcGAAAIBgAACQYAA