Error on receiving attachments on Zoho Mail

Error on receiving attachments on Zoho Mail

Hello.
On my domain  brasilchavesbh.com.br,  I have received some attachments in body of text, like this:

begin 660 Cob_BRASIL_CHAVE_F4285P1.pdf 
M)5!$1BTQ+C(-"C$@,"!O8FH@/#P-"B]#<F5A=&EO;D1A=&4H1#HR,#$W,#0P 
M-3$T,C(T-2D-"B]4:71L92A";VQE=&\@+2!"86YC;R!)=&%U($%G.C,Q,#,M 
M,"!#;VYT83HR,#,V.2TU*0T*+T-R96%T;W(H1F]R=&5S4F5P;W)T("A/<&5N 
M(%-O=7)C92D@=C,N,C0H0C$T*2`@7#(U,2!#;W!Y<FEG:'0@J2`Q.3DY+3(P 
M,#@@1F]R=&5S($EN9F]R;>%T:6-A*0T*/CX@96YD;V)J#0HR(#`@;V)J(#P\ 
M#0HO5'EP92]#871A;&]G#0HO4&%G97,@,R`P(%(-"CX^(&5N9&]B:@T*-B`P 
M(&]B:B`\/`T*+U1Y<&4O6$]B:F5C="]3=6)T>7!E+TEM86=E#0HO5VED=&@@ 
M,3$-"B](96EG:'0@,C@T#0HO0V]L;W)3<&%C92]$979I8V521T(-"B]":71S 
(...)

The text is very big, and I can't view the attachment.
What the problem? Any configuration?