What are some reinforcing consequences you can deliver either immediately following the desired behavior or following a practice session– things that this particular student enjoys, wants, seeks out, etc.?
Students who respond with inappropriate outbursts when stressed or frustrated might need a strong reinforcer in order to become motivated to use appropriate self-regulation strategies. This could include earning points, tokens or stickers toward a favored activity which may include a calming activity after a practice session.
Some students who have difficulty waiting, or may fixate on the date and time for a response, could earn minutes or points toward a favored activity for each specified length of time they are able to engage in an alternate activity, or refrain from fixating.
Verbal praise, high fives, etc., would be appropriate for any successful use of visual cues, and following appropriate responses during phone call role-plays and email follow ups.
Are you using labeling and social praise to make the contingency between desired behavior and reinforcing consequence clear to the student?
What reinforcing consequences can you arrange that are more naturally or intrinsically connected to this targeted behavior?
Emphasize to the student that a successful follow-up with an employer will build a sense of satisfaction, self-confidence, and possibly lead to employment.