IgA secretion is seen in -

In its secretory form, IgA is the main immunoglobulin found in mucous secretions, including tears, saliva, sweat, colostrum, and secretions from the genitourinary tract, gastrointestinal tract, prostate, and respiratory epithelium. It is also found in small amounts in the blood Ref: Ananthanarayan & Parker's textbook of microbiology 9th edition pg:97