Sending mail through smtp adds new lines to the email's content -

we used use our own smtp servers sending emails, started migrating of our emails sent through sendgrid, working smoothly except email's content gets breaked new lines after extent

please check email breaked content

--bayt_2660.59000399_bayt content-type: application/octet-stream content-disposition:attachment; filename="cv_report.xls"  date created,cv id,first name,middle name,last name,user name,,home  phone,work phone,mobile phone,email address,nationality,country,city,p. o.  box,address (line 1),address (line 2),gender,residence location,notice  period,last monthly salary,education degree,education location,educational  institution,completion date of education,education description,work  experience date,work experience date,work experience job  title,work experience company name,work experience description,work  experience location,work experience job role,work experience company  industry,skill name,skill level,skills years of experience,skills last  used,language name,language level 2008-06-17,3959854,t12345,mars,t12345,t12345,1986-11-11,12-12-12,12-12-12,12-12-12,test_xx@bayt.net,bahrain,belgium,,,,,,belgium,immediately,0,high  school or equivalent,,,,,,,,,,,technology/it,information technology,,,,,, 

and old our smtp servers.

--bayt_-142109.046263_bayt content-type: application/octet-stream content-disposition:attachment; filename="cv_report.xls"  date created,cv id,first name,middle name,last name,user name,,home phone,work phone,mobile phone,email address,nationality,country,city,p. o. box,address (line 1),address (line 2),gender,residence location,notice period,last monthly salary,education degree,education location,educational institution,completion date of education,education description,work experience date,work experience date,work experience job title,work experience company name,work experience description,work experience location,work experience job role,work experience company industry,skill name,skill level,skills years of experience,skills last used,language name,language level 2008-06-17,3959854,t12345,mars,t12345,t12345,1986-11-11,12-12-12,12-12-12,12-12-12,test_xx@bayt.net,bahrain,belgium,,,,,,belgium,immediately,0,high school or equivalent,,,,,,,,,,,technology/it,information technology,,,,,, 

the line breaks having huge effects if email contained csv file attachment images showed, "home phone" single value breaked 2 lines sendgrid smtp server, there idea or hint on caused line breaks?

found answer in question

how send csv attachment lines longer 990 characters

i had encode csv content base64 , add content-transfer-encoding: base64 header