I'm a sport teacher at local university and during pandemic time I have to send to my students information required for study. I have about 700 students and if I have to send them instruction. study materials, Yahoo is the worst e-mail service for this purpose. I'm always receiving error messages. I always have to generate new application key to continue sending my mails and this not helping me. I know that Yahoo is strongly fighting agains spam mailing. But what I'm doing is not a spam. Unfortunately I can't switch to another mail system until summer and suffering from the poor yahoo service. please let me know if somehow it is possible to solve my problem.