Have read other questions on this but haven't read any solutions.
Using Drupal 7.64 with CiviCRM 5.10.4.
Sent out a bulk email (newsletter) using CiviCRM last Friday to a group of 2100 members. This is our first bulk email of this size using CiviMail (previous emails have gone to <200 users), and most emails were imported into CiviCRM from other databases (Mailchimp, internal spreadsheets, etc). So there is a likely possibility that some of the email addresses that are now in CiviCRM need to be cleaned, are no longer used, have input errors from the spreadsheets, etc.
Just checked the report today and saw a 40% bounce rate, and most of the bounce rate reasons are listed as "Syntax" with no further information, when I look at the Bounce Report from the mail in CiviMail.
The recipients have a variety of email providers - hotmail, gmail, yahoo, work servers... and 60% of the emails were delivered to a variety of email providers as well.
Did some digging into my server / cpanel and looked at the mail delivery report, and saw this as a snippet from the mail delivery report. Note that Caitlyn's email was listed as both an email to be discarded (red), and also an email that was accepted (green) (it was also listed as yellow, an email to be re-attempted later).
Does anyone know how this can be fixed? Or what the issue is? I'm also wondering if there's a way to resend the newsletter only to the email addresses that bounced.
I know our emails are "staggered" (not sure of the correct term), where a small amount of emails are sent every 5 minutes, so they're not all going out at once.
I also exported CiviCRM's ConfigAndLog file from the file manager but not sure if there's anything of worth in it since it's so lengthy and way beyond my scope. But let me know if it might be useful and I can upload it here.