While sending an email as SMS, if the length is > 160 characters(GSM 7bit encoding), then have to split the message upto max of 160 and send it one by one. when spliting the message, we have to include UDHeader to identify the message is concatenation and email. For Email referring, in the UDheader IEI = 20 , IEDL = 01 IED = number of septets of RFC 822 email header. how can we get total number of septets for RFC 822 Email header?
You need to be aware that when you have concatenated messages using 7bit packing, the text in all the fragments is packed 7 bit with any padding bits on the end !! the data (in the user data header) is always sent 8bit. From memory, its been a few years since i had to do this), the header field counts need to calculate the septets for both the text and the data.
I have some software which allows this to be done correctly