Delays in delivering emails (sometimes, not always)

[amickan]

I've been noticing significant delays in email delivery via send.mail() - up to 1,5 hours. It does not seem to depend on the server I'm mailing it to (I've tried multiple different ones, and even within the same recipient some emails gets there immediately and some takes a while). R also does not report an error, the debugging ends in the usual "Queued mail for delivery". The content always was the same, the recipient(s) as well. I'm still in the setting-up phase of my script, and was wondering whether that was normal, and if not, where to look for the issues / how to fix it.

I'm working on a Windows computer and I used the following configuration:
smtp = list(host.name = "email.gwdg.de", port = 587, user.name = "xxx", passwd = "xxx", tls = TRUE),

Thanks already!

Anne