Email Providers

Ive been using emails for a some methods im doing and after I sent out so many emails my yahoo wont let me send out any more saying its suspicious activity..thing is even if i use another account on yahoo they let me send like one out then its the same thing..i even tried aol and gmail a couple emails later same thing..says theres a problem..im wondering why this is happening all of a sudden and what i can do about it? Also one in a while theyll ask me to type in some letters but I cant see any letter just an X..was wondering if theres a setting to change to see it?

It sounds like you're sending all these emails from the same IP. Try using a proxy...