ATLief's questions

Suppose you have two RAID arrays, one with N disks and one with N+1 disks. The array with N disks was formatted as a RAID 5 and left alone, while the other array was formatted as a RAID 6 before one of its disks was removed. Now both arrays have N disks, N-1 disks worth of usable storage, and can survive the loss of one (more) disk.

Besides whatever metadata the RAID controller uses, are there any differences between these two arrays (in terms of data layout, performance, and reliability)? Could I convert a RAID 6 array with one disk missing to a RAID 5 of one less expected disk with minimal "reshaping"/"rewriting"?

I know that there are different "policies"/"alignments" within RAID 5 and RAID 6, but that's probably beyond the scope of this question. Perhaps it should be assumed that both arrays use a policy that is common to both RAID levels.

Are there any large, reputable MTAs (like gmail, hotmail, icloud, etc) that will bounce mail or otherwise fail to deliver if the receiving MTA doesn't support STARTTLS?

Put another way, will reputable MTAs generally retry delivery without TLS if an attempt to STARTTLS is unsuccessful?

I have postfix and a local LMTP server running. In my main.cf, I have append_at_myorigin = no. When I run postconf|grep append_at_myorigin I get that this value is no.

But for some reason, postfix is still appending myorigin to non-FQDNs (i.e. sending to user becomes user@my-devices-hostname), and unsurprisingly the LMTP server has no idea what to do with these rewritten addresses.

Why is postfix doing this, and how can I make it stop?