Can having too many emails stored in Mail cause problems?

Question

I've got over 3,800 emails in my inbox and I sometimes have problems with Mail not starting. My mail is stored in iCloud (so I can access them across all my Apple devices) but I also have a lot of old emails just stored on my Mac.
Should I just archive old important emails on my Mac as well as deleting unwanted emails? Will that improve the performance of Mail? Would having a lot of old emails just stored on my Mac affect the performance of Mail on my Mac?
Thanks.

Answer 1

process limit
bcm@bcm-laptop:~$ ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 20
file size               (blocks, -f) unlimited
pending signals                 (-i) 16382
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) unlimited
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited