Hi ringoi37109988 ,
Could you please tell if this is happening with this document only or with all the documents?
Also what version of Acrobat Reader do you have?
On what device the recipient is opening this document also what version of Acrobat does he/she have?
Is the recipient can read the document on desktop?
Are the fonts embedded? (File->Properties->Fonts tab). Looks like the recipient does not display the fonts correctly!
One solution is to create an image file and sending that over, either as PDF or as JPG (if the document is a one page one).