Para criar as tabelas no PostgreSql para utilizar o calendário e o captcha, execute os seguintes
creates:

CREATE TYPE cond AS ENUM (
    'PUBLIC',
    'PRIVATE',
    'DEPT'
);

CREATE TYPE ocupation AS ENUM (
    'MEETING',
    'BUSY',
    'TRIP',
    'TEMP'
);

CREATE TYPE res AS ENUM (
    'YES',
    'NO'
);

CREATE TYPE resposta AS ENUM (
    'C',
    'U',
    'D'
);

CREATE TYPE stat AS ENUM (
    'A',
    'P',
    'U'
);

CREATE TABLE displayed
(
  fk_event integer NOT NULL DEFAULT 0,
  username character varying(32) NOT NULL DEFAULT ''::character varying,
  CONSTRAINT displayed_pkey PRIMARY KEY (fk_event, username)
)
WITH (OIDS=FALSE);
ALTER TABLE displayed OWNER TO postgres;

CREATE TABLE error_login
(
  users character varying(15) NOT NULL,
  id serial NOT NULL,
  date timestamp with time zone DEFAULT now(),
  ip character varying(18),
  count_attempts character varying(5)
)
WITH (OIDS=FALSE);
ALTER TABLE error_login OWNER TO postgres;

CREATE TABLE events
(
  id integer NOT NULL,
  subject character varying(128) DEFAULT NULL::character varying,
  "location" character varying(128) DEFAULT NULL::character varying,
  event_start integer,
  event_end integer,
  isallday character varying(5) NOT NULL DEFAULT 'NO'::character varying,
  notime character varying(5) NOT NULL DEFAULT 'NO'::character varying,
  istask character varying(5) NOT NULL DEFAULT 'NO'::character varying,
  isholiday character varying(5) NOT NULL DEFAULT 'NO'::character varying,
  isalarm character varying(5) NOT NULL DEFAULT 'NO'::character varying,
  alarmbeforeminutes integer,
  priority smallint DEFAULT (5)::smallint,
  created_on integer,
  last_modified_on integer,
  comments text,
  classification character varying(15) DEFAULT 'BUSY'::character varying,
  eventfrom character varying(32) NOT NULL DEFAULT ''::character varying,
  "domain" character varying(20) NOT NULL DEFAULT 'PRIVATE'::character varying,
  dept integer NOT NULL DEFAULT 0,
  status character varying(2) NOT NULL DEFAULT 'P'::character varying,
  is_mail_notified character varying(32),
  CONSTRAINT events_pkey PRIMARY KEY (id)
)
WITH (OIDS=FALSE);
ALTER TABLE events OWNER TO postgres;

-- Index: end_idx

-- DROP INDEX end_idx;

CREATE INDEX end_idx
  ON events
  USING btree
  (event_end);

-- Index: isholiday_idx

-- DROP INDEX isholiday_idx;

CREATE INDEX isholiday_idx
  ON events
  USING btree
  (isholiday);

-- Index: istask_idx

-- DROP INDEX istask_idx;

CREATE INDEX istask_idx
  ON events
  USING btree
  (istask);

-- Index: start_idx

-- DROP INDEX start_idx;

CREATE INDEX start_idx
  ON events
  USING btree
  (event_start);

CREATE TABLE events_seq
(
  id serial NOT NULL,
  CONSTRAINT events_seq_pkey PRIMARY KEY (id)
)
WITH (OIDS=FALSE);
ALTER TABLE events_seq OWNER TO postgres;



CREATE TABLE files
(
  fk_event integer NOT NULL DEFAULT 0,
  file_name character varying(255) NOT NULL DEFAULT ''::character varying,
  content_type character varying(64) NOT NULL DEFAULT ''::character varying,
  file_raw bytea NOT NULL
)
WITH (OIDS=FALSE);
ALTER TABLE files OWNER TO postgres;

-- Table: members

-- DROP TABLE members;

CREATE TABLE members
(
  username name NOT NULL DEFAULT ''::bpchar,
  fk_event integer NOT NULL DEFAULT 0,
  response resposta NOT NULL DEFAULT 'U'::resposta
)
WITH (OIDS=FALSE);
ALTER TABLE members OWNER TO postgres;

-- Table: users

-- DROP TABLE users;

CREATE TABLE users
(
  username character(32) NOT NULL DEFAULT ''::bpchar,
  "level" integer NOT NULL DEFAULT 0,
  department integer NOT NULL DEFAULT 0,
  CONSTRAINT users_pkey PRIMARY KEY (username)
)
WITH (OIDS=FALSE);
ALTER TABLE users OWNER TO postgres;

CREATE TABLE users_email
(
id serial NOT NULL,
"name" character varying(26)
)
WITH (OIDS=FALSE);
ALTER TABLE users_email OWNER TO postgres;
COMMENT ON TABLE users_email IS 'Tabela que contém todos os usuários do webmail';

INSERT INTO members ( username , fk_event , response ) VALUES ('', '0',     'D');
INSERT INTO events_seq values (1);
 

Criei o banco: createdb emexis-webmail e execultei os comandos acima de criação de tabela.

Apareceu este erro na tela de login:

Fatal error: Call to undefined function pg_connect() in /var/www/htdocs/emexis-webmail/plugins/captcha/setup.php on line 85

Comentei o plugin captch: A apareceu este erro:

ERROR : * Postgresql extensions is not installed. * Pear::DB is not installed. CHECK INSTALL INSTRUCTIONS.

e

#################

Warning: include_once(DB.php) [function.include-once]: failed to open stream: No such file or directory in /var/www/htdocs/emexis-webmail/plugins/pcal/load_prefs.php on line 16

Warning: include_once() [function.include]: Failed opening 'DB.php' for inclusion (include_path='.:/usr/lib/php') in /var/www/htdocs/emexis-webmail/plugins/pcal/load_prefs.php on line 16

Olá Edineudo o primeiro erro, significa que o suporte do postgres para o seu PHP não está instalado, crie um arquivo em php com:

 phpinfo();

Coloque na raiz do seu apache e rode, verifique o suporte para o postgres. O segundo erro é porque o seu PHP está sem suporte ao PEAR, verifique: http://eos.brc.com.br/index.php/pt/forum/view-postlist/forum-4-how-to/topic-24-dependencias-do-calendario-instalando-o-framework-pear Qualquer dúvida entre em contato