I have the exactly the same problem starting since Thursday, May 7, 2020.
I have 3 accounts, 1 corp exchange acct, one gmail acct and one yahoo mail acct. only yahoo mail acct is failing with tls issue ""Error performing TLS handshake: Internal error in memory allocation.". (imap.mail.yahoo.com:993).
the other two accts work great.
Evolution 3.28.5-0ubuntu0.18.04.2 on Ubuntu 18.04.
I have the exactly the same problem starting since Thursday, May 7, 2020.
I have 3 accounts, 1 corp exchange acct, one gmail acct and one yahoo mail acct. only yahoo mail acct is failing with tls issue ""Error performing TLS handshake: Internal error in memory allocation.". (imap.mail. yahoo.com: 993).
the other two accts work great.
Evolution 3.28.5- 0ubuntu0. 18.04.2 on Ubuntu 18.04.