Error message XS850 'Cannot process message; maximum size exceeded'

Solving error no. XS850 error 'Cannot process message; maximum size exceeded':

So requirement is to issue email notification from background job with spool request as an attachment in it. 

Prerequisites:

(a) Create background job via SM36 t-code, by enabling sending email notification with spool requests in it:

(b) Schedule background job via SM36 t-code 

(c) Add email receiver under SMTP node via SCOT t-code:

(d) In my case attachment size is ca 3 MB, hence need to extend MAXLEN_BODYPART_ALI_SMTP  parameter size to 3 MB accordingly via SM30 t-code in SXPARAMS configuration view: