this is a message from poloniex:
SBD is currently under maintenance or experiencing wallet/network issues. Deposits and withdrawals will remain disabled until a solution is found, which may require an update from the SBD team. Any updates must be tested and audited before enabling.
I transferred some SBD yesterday and it never arrived on my poloniex account.
When I signed up to their support system to ask about the problem, I instantly got an automated email to inform me about the problem and now it's also on the site.
I have no idea what's wrong, but ... for now you can't withdraw or deposit SBD using poloniex and I have no idea when it will be resolved, I just want to warn people, so, please ... resteem this posts to spread the message.
cheers,
a fellow Steemian